Gilera Nexus 500 Workshop Manual Download Page 111

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- Remove the by-pass and the relevant spring.

- Remove the oil pump seal.

Removing the stator

- Remove the two retaining screws and the cable

guide bracket.

- Unscrew the 3 fastening screws and remove sta-

tor and its wiring.

- Loosen the two retaining screws and remove the

reed valve support with bulkhead.

Nexus 500

Engine

ENG - 29

Summary of Contents for Nexus 500

Page 1: ...WORKSHOP MANUAL 633309 Nexus 500 ...

Page 2: ...mponents parts or accessories which it considers necessary to improve the product or which are required for manufacturing or construction reasons Not all versions shown in this publication are available in all countries The availability of single versions should be checked at the official Piaggio sales network Copyright 2005 PIAGGIO C S p A Pontedera All rights reserved Reproduction of this public...

Page 3: ...ections of this manual relating to specific tools along with the specific tool catalogue N B Provides key information to make the procedure easier to understand and carry out CAUTION Refers to specific procedures to carry out for preventing damages to the vehicle WARNING Refers to specific procedures to carry out to prevent injuries to the repairer Personal safety Failure to completely observe the...

Page 4: ......

Page 5: ...STICS CHAR TOOLING TOOL MAINTENANCE MAIN ELECTRICAL SYSTEM ELE SYS ENGINE FROM VEHICLE ENG VE ENGINE ENG INJECTION INJEC SUSPENSIONS SUSP BRAKING SYSTEM BRAK SYS COOLING SYSTEM COOL SYS CHASSIS CHAS PRE DELIVERY PRE DE TIME TIME ...

Page 6: ......

Page 7: ...INDEX OF TOPICS CHARACTERISTICS CHAR ...

Page 8: ...g the compressed air jet so as to not inhale the dust produced by the wear of the friction material Even though the latter contains no asbestos dust inhalation is harmful Maintenance rules Use original PIAGGIO spare parts and lubricants recommended by the Manufacturer Non original or non conforming spares may damage the vehicle Use only the special tools designed for this scooter Always use new ga...

Page 9: ...s WEIGHT Specification Desc Quantity Dry weight 199 kg Width 765 mm Length 2090 mm Wheel base 1515 mm Saddle height 780 mm Height 1045 mm Engine ENGINE Specification Desc Quantity Engine single cylinder four stroke Bore 92 mm Stroke 69 mm Cubic capacity 460 cm Compression ratio 10 5 1 Nexus 500 Characteristics CHAR 3 ...

Page 10: ...x power at crankshaft 29 5 kW at 7500 rpm Max torque at crankshaft 43 Nm at 5500 rpm Cooling system Fluid circulation through a motor driven pump 3 way thermostat and electric fan Transmission TRANSMISSIONS Specification Desc Quantity Transmission With automatic expandable pulley variator with tor que server V belt automatic clutch gear reduc tion unit and transmission housing with forced air circ...

Page 11: ...e strut it is possible to modify the geometry and balance of the rear axle 15 positions The motor has a fixed connection to the frame by means of a shaft direct link Brakes BRAKES Specification Desc Quantity Front brakes Twin discs of stainless steel dia 260 mm with floating calliper and twin 28 mm diameter plungers Brembo at front right and twin 26 mm diameter plungers Brembo at front left Rear b...

Page 12: ...DER AND ACCESSORIES CAUTION IT IS MANDATORY TO ADOPT EXCLUSIVELY S CLASS TYRES WHICH GUARANTEE COR RECT VEHICLE PERFORMANCE AT THE DIFFERENT SCOOTER SPEEDS USING ANY OTHER TYRE MAY RESULT IN VEHICLE INSTABILITY IT IS ADVISABLE TO USE TYRE TYPES REC OMMENDED BY PIAGGIO Tightening Torques FRAME Name Torque in Nm Electric pump locking ring nut 20 BRAKE SYSTEM Name Torque in Nm Brake calliper coupling...

Page 13: ...astening screws 33 37 Tighten and loosen completely Tighten and loosen by 90 REAR SUSPENSION Name Torque in Nm Engine chassis fixing pin 100 120 Central stand retainers 25 30 Muffler heat guard retainers 6 8 Side stand clamp 15 20 Rear wheel axle 104 126 Connection of rear shock absorber to support con necting rod 38 46 Rear shock absorber retainer to the chassis 38 46 Upper strut connection 56 70...

Page 14: ...upling screws 11 13 Oil pump screws 5 6 Gear mounting on crankshaft screws 10 12 Bulkhead screws for oil pump housing cover 8 10 FINAL REDUCTION Name Torque in Nm Rear hub cover screws 24 27 TRANSMISSION COVER Name Torque in Nm Driven pulley nut 92 100 Drive pulley nut 160 175 Anti vibration roller screw 16 7 19 6 M8 retainers for transmission cover 23 26 M6 retainer 11 13 Anti vibration roller re...

Page 15: ...que of the bolts Part No 841311 has been changed from 8 10 Nm to 14 16 Nm in order to avoid a possible loosening of the muffler We wish to inform you that the correct tightening torque for attachment of the chassis rocker arm is 100 110 Nm and not 10 11 Nm as incorrectly indicated in the Technical Note 14 2004 Overhaul data This section provides the main information for scooter servicing Assembly ...

Page 16: ... ring inside the cylinder Ring opening SEALING RINGS Name Initials Cylinder Piston Play on fitting 1st Compression ring A 0 15 0 35 0 5 Middle piston ring A 0 25 0 50 0 65 Oil scraper ring A 0 25 0 50 0 65 Crankcase crankshaft connecting rod Crankcase countershaft coupling Besides considering it should match the crankshaft the crankcase is chosen according to the centre to centre distance between ...

Page 17: ... considered universal and can be fitted to either crankcase type Either the pair of gears or the crankcase is identified with the letter referring to the type on the crank case this mark is found at the cylinder mouth flywheel side Diameter of crankshaft bearings Measure the capacity on both axes x y CRANKSHAFT Specification Desc Quantity Cat 1 Standard diameter 40 010 40 016 Cat 2 Standard diamet...

Page 18: ... 0 025 A D 0 20 0 40 Transmission side half shaft 19 6 0 050 B D 0 20 0 40 Connecting rod 22 0 10 0 15 C D 0 20 0 40 Flywheel side shoulder 13 0 025 F D 0 20 0 40 Flywheel side half shaft 19 6 0 050 E D 0 20 0 40 Complete drive shaft 63 5 0 1 0 05 G D 0 20 0 40 Characteristic Drive shaft crankcase axial clearance 0 1 0 5 mm when cold Characteristics Nexus 500 CHAR 12 ...

Page 19: ...E OTHER HAND THE MORE THE PISTON TOP IS RECESSED INTO THE CYLINDER TOP PLANE THE SMALLER THE GASKET THICKNESS BASE GASKET THICKNESS Name Measure A Thickness A MEASURE TAKEN 0 185 0 10 0 4 0 05 A MEASURE TAKEN 0 10 0 10 0 6 0 05 A MEASURE TAKEN 0 10 0 185 0 8 0 05 N B VALUES INDICATED WITH REFER TO PISTON CROWN RECESSES WITH RESPECT TO THE CYLINDER PLANE Products PRODUCTS Product Description Specif...

Page 20: ...ant Monoethylene glycol based anti freeze fluid CUNA NC 956 16 AGIP EXTRA POLISH Muffler cleaning paste special product for cleaning and polishing stainless steel muffler AGIP GP 330 Grease for brake levers throttle White calcium complex soap based spray grease with NLGI 2 ISO L XBCIB2 AGIP CITY TEC 2T Mixer oil synthetic oil for 2 stroke engines JASO FC ISO L EGD Characteristics Nexus 500 CHAR 14...

Page 21: ...INDEX OF TOPICS TOOLING TOOL ...

Page 22: ... steering seats 001467Y002 Driver for OD 73 mm bearing 001467Y006 Pliers to extract 20 mm bearings 001467Y007 Driver for OD 54 mm bearing 001467Y008 Pliers to extract 17 mm ø bear ings 001467Y014 Pliers to extract ø 15 mm bear ings Tooling Nexus 500 TOOL 2 ...

Page 23: ...034 Extraction pliers for ø 15 mm bearings 001467Y035 Belle for OD 47 mm bearings 002465Y Pliers for circlips 006029Y Punch for fitting fifth wheel seat on steering tube 020004Y Punch for removing fifth wheels from headstock Nexus 500 Tooling TOOL 3 ...

Page 24: ...for steering tube ring nut 020150Y Air heater support 020151Y Air heater 020193Y Oil pressure gauge 020201Y Spacer bushing driving tube 020262Y Crankcase splitting strip 020306Y Punch for assembling valve seal rings Tooling Nexus 500 TOOL 4 ...

Page 25: ... Description 020329Y MityVac vacuum operated pump 020330Y Stroboscopic light for timing con trol 020331Y Digital multimeter 020333Y Single battery charger 020334Y Multiple battery charger Nexus 500 Tooling TOOL 5 ...

Page 26: ...netic support for dial gauge 020357Y 32 x 35 mm adaptor 020358Y 37x40 mm adaptor 020359Y 42x47 mm adaptor 020360Y Adaptor 52 x 55 mm 020364Y 25 mm guide 020376Y Adaptor handle 020382Y012 bush valve removing tool Tooling Nexus 500 TOOL 6 ...

Page 27: ...res code Description 020412Y 15 mm guide 020424Y Driven pulley roller casing fitting punch 020431Y Valve oil seal extractor 020434Y Oil pressure control fitting 020439Y 17 mm guide Nexus 500 Tooling TOOL 7 ...

Page 28: ...removing the driv en pulley clutch 020456Y Ø 24 mm adaptor 020458Y Puller for lower bearing on steer ing tube 020459Y Punch for fitting bearing on steer ing tube 020460Y Scooter diagnosis and tester 020467Y Flywheel extractor Tooling Nexus 500 TOOL 8 ...

Page 29: ...iption 020468Y Piston fitting ring 020469Y Reprogramming kit for scooter diagnosis tester 020470Y Pin retainers installation tool 020471Y Pin for countershaft timing 020472Y Flywheel lock wrench Nexus 500 Tooling TOOL 9 ...

Page 30: ...74Y Driving pulley lock wrench 020475Y Piston position checking tool 020476Y Stud bolt set 020478Y Punch for driven pulley roller cas ing 020479Y Countershaft lock wrench 020480Y Petrol pressure check set Tooling Nexus 500 TOOL 10 ...

Page 31: ...20481Y Control unit interface wiring 020482Y Engine support 020483Y 30 mm guide 020512Y Piston fitting fork 020527Y Engine support base 020604Y011 Fitting adapter 020565Y Flywheel lock calliper spanner Nexus 500 Tooling TOOL 11 ...

Page 32: ...Stores code Description 020623Y Pre service gas extraction set 020625Y Kit for sampling gas from the ex haust manifold 494929Y Exhaust fumes analyser Tooling Nexus 500 TOOL 12 ...

Page 33: ...INDEX OF TOPICS MAINTENANCE MAIN ...

Page 34: ... specified times even if the stated mileage has not yet been reached Carrying out scheduled services on time is necessary to ensure your warranty remains valid For any further information concerning Warranty procedures and Scheduled Mainte nance please refer to the Warranty Booklet EVERY 2 YEARS 60 Action Coolant change Brake fluid change EVERY 3 000 KM Action Engine oil level check top up Brake p...

Page 35: ...tion Engine oil replacement Hub oil level check Spark plug electrode gap replacement Air filter clean Engine oil change Carburetion check adjust Seals injection system hoses visual check Base vent check Variable speed rollers replacement Roller support sliding blocks check change Driving belt replacement Coolant level check Steering adjustment Brake control levers greasing Transmission elements lu...

Page 36: ...njection system hoses visual check Base vent check Variable speed rollers replacement Roller support sliding blocks check change Driven pulley bushing check grease Driving belt replacement Coolant level check Steering adjustment Brake control levers greasing Transmission elements lubrication Brake fluid level check Safety locks check Suspensions check Electrical system and battery check Headlight ...

Page 37: ...heck Steering adjustment Brake control levers greasing Brake fluid hoses replacement Transmission elements lubrication Brake fluid level check Safety locks check Suspensions check Electrical system and battery check Headlight adjustment Tyre inflation and wear Check Vehicle and brake test road test AFTER 48 000 KM 255 Action Engine oil replacement Hub oil change Spark plug electrode gap replacemen...

Page 38: ...lve clearance check Carburetion check adjust Seals injection system hoses visual check Base vent check Variable speed rollers replacement Roller support sliding blocks check change Driven pulley bushing check grease Driving belt replacement Coolant level check Radiator external cleaning check Steering adjustment Brake control levers greasing Brake fluid hoses replacement Brake fluid level check Sa...

Page 39: ...k plug cap Unscrew the spark plug Check the conditions of the spark plug make sure the insulation is intact that the electrodes are not excessively worn or grimy the conditions of the washer and measure the distance between the elec trodes using the appropriate feeler gauge Characteristic Electrode gap 0 7 0 8 mm Adjust the gap if necessary carefully bending the earth electrode In the event of irr...

Page 40: ...the oil dipstick dry it with a clean cloth and reinsert it screwing it in thoroughly Pull out the dipstick and check that the oil level is between the MAX and MIN notches indicated on the dipstick if the level is below the MIN value re store the proper amount of oil in the hub Retighten the oil dipstick again and make sure it is locked properly into place Replacement Prepare a suitable container R...

Page 41: ... the oil filler plug Characteristic Rear hub oil Capacity approximately 250 cc Recommended oil TUTELA ZC 90 Air filter Raise the saddle Remove the piston ring and the battery cover Loosen the 4 mounting screws shown in the fig ure Loosen the mounting screw located under the in take manifold Nexus 500 Maintenance MAIN 9 ...

Page 42: ...RICATION AS WITH A SOILED FILTER CAUSES AN EXCESSIVELY RICH FUEL AIR MIXTURE CAUTION WHEN TRAVELLING ON DUSTY ROADS THE AIR FILTER MUST BE CLEANED MORE OFTEN THAN SHOWN IN THE SCHEDULED MAINTENANCE CHART WARNING DO NOT RUN THE ENGINE IF THE AIR FILTER IS NOT IN PLACE THIS WILL RESULT IN EXCES SIVE WEAR TO ALL THE PARTS OF THE COOLING SYSTEM Engine oil In 4T engines the engine oil is used to lubric...

Page 43: ...gine the level line will be lower in order to carry out a correct check it is necessary to wait at least 10 minutes after the engine has been stopped so as to get the correct level Oil top up The oil should be topped up after having checked the level and in any case by adding oil without ever exceeding the MAX level The restoration level between the MIN and MAX levels implies a quantity of oil of ...

Page 44: ...w until it comes into contact with the seal and further tighten to the prescribed torque Refit the muffler Add recommended engine oil Start the engine and let it run for a few minutes and then turn it off After 5 minutes check the level and top up if necessary never exceed the MAX level N B IF THE OIL IS CHANGED WITHOUT CHANGING THE CARTRIDGE FILTER 1ST COUPON ADD AROUND 1500 CC OF OIL INSTEAD OF ...

Page 45: ...pond to the in dicated values If the clearance does not corre spond adjust it by loosening the counternut using a screwdriver on the register screw as shown in the figure Characteristic Valve clearance intake 0 15 mm when cold Valve clearance exhaust 0 15 mm when cold Cooling system If noise or loss of liquid at the drain bore of the water pump is discovered it will be necessary to overhaul the pu...

Page 46: ... To check the level it is necessary to look inside the expansion tank The reference mark in the figure shows the correct coolant level The coolant consists of an ethylene glycol and corrosion inhibitor based 50 demineralised water antifreeze solution mix CAUTION DO NOT EXCEED THE MAX LEVEL WHEN FILLING SO AS TO AVOID THE COOLANT ESCAPING FROM THE EXPANSION TANK WHEN THE vehicle IS IN USE N B THE C...

Page 47: ...pump as shown in the figure N B THE LEVEL TENDS TO DROP AS THE BRAKE PADS GET WORN A MINIMUM LEVEL SHOULD NOT BE REACHED IF THE LEVEL IS TOO LOW CHECK AND FIX THE SYSTEM SEALS IF RE QUIRED TOP UP THE PUMP TANK IF REQUIRED CONSIDERING THAT THE MAX LEVEL MUST ONLY BE OBTAINED WITH NEW PADS Top up CAUTION ONLY USE DOT 4 CLASSIFIED BRAKE FLUID Proceed as follows Rest the scooter on a flat ground and o...

Page 48: ...ON NEVER USE BRAK ING FLUID FROM CONTAINERS THAT HAVE ALREADY BEEN OPENED OR PARTIALLY USED Characteristic Prescribed fluid TUTELA TOP 4 Under normal climatic conditions the fluid must be changed every 20 000 km or anyway every two years N B SEE THE BRAKING SYSTEM CHAPTER WITH REGARD TO THE CHANGING OF BRAKE FLUID AND THE BLEEDING OF AIR FROM THE CIRCUITS Headlight adjustment Place the scooter in ...

Page 49: ...timing sensor to disable operation of the injector and sparkplug Run the engine using the starter motor and with the throttle body fully open until the reading on the pressure gauge is stable If the pressure is greater than XX XX remove the device and reassemble the vehicle If pressure values lower than those indicated are measured check the engine rpm used for the test if under 450 rpm check the ...

Page 50: ...Maintenance Nexus 500 MAIN 18 ...

Page 51: ...INDEX OF TOPICS ELECTRICAL SYSTEM ELE SYS ...

Page 52: ...se 7 5 A 11 Fuse 10 A 12 Side stand switch 13 Number plate light with bulb 12V 5W 14 Taillight with bulb 12V 21 5W 15 Front left rear right direction indicator with bulb 12V 10W 16 Front right rear left direction indicator with bulb 12V 10W 17 HV coil 18 Fuse holder terminal board 19 Saddle opening actuator 20 Socket for users 12V 180W max 21 Helmet compartment lighting glass bowl N 1 12V 5W bulb ...

Page 53: ...flywheel 47 Stepper motor for idle jet 48 Throttle position sensor 49 Engine rpm sensor 50 Injector 51 Cooling fluid temperature sensor for inj cir cuit 52 Cooling fluid temperature sensor for instru ment 53 Oil pressure sensor 54 Right electric control 55 Front brake stop button 56 Left headlight for LH drive N 1 12V 55W bulb for dipped beams n 1 12V 5W bulb for taillight Wiring colour chart B Wh...

Page 54: ...ts of the passenger footrest Overturn sensor In order to access the overturn sensor remove the central union During assembly observe the installation direction shown in the figure H V coil In order to access the high voltage coil remove the left hand side fairing Electrical system Nexus 500 ELE SYS 4 ...

Page 55: ... connector remove the wind shield with the respective support and the metal plate holding the control unit ECU decoder and saddle opener remote control N B AFTER INSERTING THE INTERFACE CABLE OR THE ELECTRONIC CONTROL UNIT RE TIGHTEN THE SCREW AND THE GROUND CA BLE Immobiliser decoder In order to access the immobilizer decoder re move the upper shield back plate Nexus 500 Electrical system ELE SYS...

Page 56: ...e upper shield back plate Specification Desc Quantity A DIODE UNIT B ELECTRIC FAN REMOTE CONTROL SWITCH C ENGINE STOP REMOTE CONTROL SWITCH D CONTROL UNIT REMOTE CONTROL SWITCH Voltage regulator To access the voltage regulator Conceptual diagrams Electrical system Nexus 500 ELE SYS 6 ...

Page 57: ...ht switches 4 Start up button 5 Fuse 7 5 A 6 Control unit remote control switch 7 Stop light 8 Fuse 5A 9 Diode 6A 10 Engine stop remote control switch 11 Starter motor 12 Engine stop indicator 13 Remote starter switch 14 Fuse 7 5 A 15 Stand switch Nexus 500 Electrical system ELE SYS 7 ...

Page 58: ...18 Key switch contacts 19 Key switch contacts 20 Battery 12V 14 Ah 21 Fuse 10 A 22 Fuse 3 A 23 Fuse 7 5 A 24 Voltage regulator 25 EMS controller 26 Decoder 27 Fuse 30A 28 Tilting sensor Headlights and automatic starter section Electrical system Nexus 500 ELE SYS 8 ...

Page 59: ...switch contacts 13 Helmet compartment lighting button 14 Helmet compartment light 15 Socket for users 12V 180W max 16 Fuse 15 A 17 Battery 12V 14 Ah 18 Rear taillight 19 Number plate light 20 N 2 front taillight bulbs 21 Taillight indicator 22 Key switch contacts 23 Fuse 3 A 24 Fuse 30A 25 Voltage regulator 26 Fuse 7 5 A 27 Fuse 7 5 A 28 Key switch contacts 29 Indicators switch 30 Hazard switches ...

Page 60: ... 5 A 3 Stoplight switches 4 Stop light 5 Starter motor 6 Key switch contacts 7 Start up button 8 Remote starter switch 9 Fuse 30A 10 Diode 6A 11 Fuse 7 5 A 12 Engine stop indicator 13 Engine stop switch 14 Stand switch 15 Battery 12V 14 Ah 16 Voltage regulator 17 Magneto flywheel Electrical system Nexus 500 ELE SYS 10 ...

Page 61: ...Fuel level sender 4 Oil pressure sensor 5 Cooling fluid temperature sensor 6 Wheel RPM sensor 7 Saddle opening receiver 8 Saddle opening actuator 9 Horn button 10 Engine stop remote control switch 11 Horn 12 Electric fan motor 13 Fuse 4 A 14 Electronic injection control unit 15 Electric fan remote control switch Nexus 500 Electrical system ELE SYS 11 ...

Page 62: ...erefore requires no connection to the key switch The three phase generator provides good recharge power and at low revs a good compromise is achieved between generated power and idle stability Stator check Stator winding check up WARNING THE CHECK UP CAN BE MADE WITH THE STATOR PROPERLY INSTALLED 1 Remove the door in the saddle compartment 2 Disconnect the connector between the stator and regulato...

Page 63: ...tive pole and the Black cable 3 With the tester terminals connected disconnect the Black cable from the battery negative pole 4 With ignition key still at OFF the reading detected by the amperometer must be 0 5 mA Maximum current output check With engine off and panel set to ON turn on the lights and let the battery voltage set to 12V Connect ammeter pliers to the 2 recharge positive poles in outp...

Page 64: ...pare fuse is provided below it The values of the fuses are printed on the fuse holder terminal boards CAUTION BEFORE REPLACING THE BLOWN FUSE SEARCH AND ELIMINATE THE BREAKDOWN THAT HAS LED TO THE BLOW OUT NEVER TRY TO REPLACE A FUSE USING DIF FERENT MATERIAL FOR EXAMPLE A PIECE OF ELECTRIC WIRE OR A FUSE FOR A HIGH ER AMPERAGE THAN THE INDICATED ONE Electrical system Nexus 500 ELE SYS 14 ...

Page 65: ...upply 5 7 5 A Horn Emergency stop indicator Un der key instrument unit power supply Flashing lights con trol 6 15A Lighter Helmet compartment light FUSE HOLDER B COUNTER SHIELD Specification Desc Quantity 1 3 A Immobilizer decoder power supply Injec tion control unit pow er supply 2 5 A Injection control unit under key 3 7 5 Stop light Remote starter switch coil 4 7 5 Lower beam 5 10 A Dipped beam...

Page 66: ...MODE button for more than 3 second to reset the kilometers of the selected icon in the SERVICE function it also resets the date N B The date must be adjusted upon the vehicle delivery to the customer since the SERVICE icon is also based on time besides the kilometers If the clock has already been started upon delivery reset the SERVICE function The vehicle is provided with an instrument panel divi...

Page 67: ... SET The LCD panel provides a 5 digit display for the visualisation of Total kilometres Trip kilometres Clock N B IT IS POSSIBLE TO CHANGE THE DISPLAY TO KM OR MILES BY PRESSING THE BUTTONS MODE AND CLOCK SIMULTANEOUSLY FOR LONGER THAN 3 SECONDS AT THE MOMENT YOU TURN THE KEY TO POSITION ON THE WORD SET WILL BE DISPLAYED Pushing the MODE button for less than a second displays the following functio...

Page 68: ...bols BELT Indicates the need to replace the transmission belt This lamp should come on and flash every 12000 km SERVICE Service coupon Indicates the need to carry out the scheduled maintenance operations The lamp should come on after reaching 1000 km or 1 year after initial activation then every 6000 km or 1 year after the last activation WARNING THE SCOOTER SHOULD BE SERVICED IN ANY CASE AT THE K...

Page 69: ...isplay will automatically show the modified date Sealed battery Sealed battery start up operations If the vehicle is provided with a sealed battery the only maintenance required is the check of its charge and recharging if necessary These operations should be carried out before delivering the vehicle and on a six month basis while the vehicle is stored in open circuit Besides upon pre delivery it ...

Page 70: ...runs down completely in the course of three months If it is necessary to refit the battery in the vehicle be careful not to reverse the connections remembering that the ground wire black marked must be connected to the negative clamp while the other two red wires marked must be con nected to the clamp marked with the positive sign Dry charge battery Remove the short closed tube and the caps then p...

Page 71: ... and it must therefore be recharged If the scooter is not used for a given time 1 month or more it will be necessary to periodically recharge the battery The battery runs down completely in the course of three months When refitting the battery onto the scooter pay attention not to invert the cables bearing in mind that the earth black wire marked with a must be connected to the negative terminal w...

Page 72: ...system Turn the key switch to ON Access the tone wheel connector on the system side Carry out the following measurements using the special tool Specific tooling 020331Y Digital multimeter Check the supply voltage Keeping the connector in the position shown in the photo check for battery voltage 12 V with the polarity shown If incorrect values are measured check the elec trical system and the digit...

Page 73: ...86 electric fan remote control switch 6 Stepper motor Stepper motor 7 Engine rpm sensor 8 9 EMS diagnostic connector 10 EMS diagnostic connector 11 Throttle potentiometer signal 12 Engine rpm sensor 13 Injector control negative 14 Stepper motor Stepper motor 15 Instrument panel injection warning light negative 16 Decoder serial Overturn sensor 17 Base power supply positive 18 Air temperature senso...

Page 74: ...R SADDLE OPENER Specification Desc Quantity 1 Radio aerial 2 Actuator positive output 1 3 Reset Input cancel 4 Battery positive 5 Not connected 6 Live positive 7 Earth 8 Not connected 9 Not connected 10 Selection input CH1 CH3 11 Positive output actuator 1 12 Data for alarm output Immobiliser decoder IMMOBILIZER DECODER Specification Desc Quantity 1 2 Immobilizer LED control negative Electrical sy...

Page 75: ...al 7 8 Continuous power supply positive Immobilizer aerial Engine rev sensor REV SENSOR Specification Desc Quantity 1 M Male 2 F Female 3 S Shielding Dashboard The instrument panel is provided with two connec tors A with 20 pins and B with 12 pins shown in the figure Nexus 500 Electrical system ELE SYS 25 ...

Page 76: ... 12 Immobilizer LED 13 Permanent power supply 14 Turn indicator assembly 15 Pump level sensor 16 17 Injection LED 18 Right turn indicator warning light 19 Left turn indicator warning light 20 Emergency warning flashers Connector B KEY 1 Rpm indicator D 2 Rpm indicator B 3 4 5 ICP ID NEXUS 500 6 ICP ID NEXUS 250 7 Rpm indicator C 8 Rpm indicator A 9 10 11 12 ICP ID COMAND ID Electrical system Nexus...

Page 77: ...device If the remote control is lost a new one can be requested and programmed by resetting the ECU memory and following the same steps as per programming the immobilizer system in the keys Battery replacement The remote control for the black key is powered by inner batteries that get discharged after extended use You may need to replace the batteries if the re mote control fails or if its range o...

Page 78: ...gramming Follow these steps to program the remote controls 1 Insert the remote control key to be programmed in the steering lock key block 2 Turn the key to ON press the button of the remote control release the button turn the key from ON back to OFF all within four seconds 3 Wait for 1 to 8 seconds 4 Repeat steps 2 and 3 for 4 times without removing the key The control unit confirms the programmi...

Page 79: ...INDEX OF TOPICS ENGINE FROM VEHICLE ENG VE ...

Page 80: ... shown in the figure so as to loosen the muffler strap and remove the whole muffler N B DUE TO MUFFLER DIMENSIONS IT IS NOT POSSIBLE TO ACTUATE ON THE SCREW PERPENDICULARLY TO REMOVE IT USE A COMMERCIALLY AVAILABLE BONDUS MALE HEXAGONAL WRENCH Removal of the engine from the vehicle Fitting the engine on the vehicle Engine from vehicle Nexus 500 ENG VE 2 ...

Page 81: ... underseat compartment Drain the coolant Remove the complete muffler assembly Remove the rear wheel Remove the swinging arm Remove the throttle control transmission Remove the air filter coupling and the collector Disconnect the ground cable from the engine Disconnect the carburettor electrical devices and the starter motor power supply cable Disconnect the fuel delivery and return pipes from the ...

Page 82: ...Engine from vehicle Nexus 500 ENG VE 4 ...

Page 83: ...INDEX OF TOPICS ENGINE ENG ...

Page 84: ...tom of the cap Loosen the driven pulley shaft fastening nut using a misaligned wrench and prevent the pulley shaft rotation using a machine hexagon bush Remove the nut and the two washers N B DUE TO THE HIGH TIGHTENING TORQUE US ING DIFFERENT WRENCHES SUCH AS A CONVENTIONAL POLYGONAL BUSH MAY DAMAGE THE HEXAGON OBTAINED ON THE SHAFT OR BREAK THE BUSH ITSELF Remove the six M6 screws Engine Nexus 50...

Page 85: ...tract the outside plastic transmission cover Air duct Remove the transmission cover Unscrew the two screws shown in the figure to remove the air conveyor Locking torques N m Air conveyor screws 11 12 Remove the external transmission cover Unscrew the 4 fastening screws shown in the fig ure to remove the external air conveyor Nexus 500 Engine ENG 3 ...

Page 86: ...urface and use the special tool so that it is adequately sup ported Pull out the bearing using the special tool N B BELL MUST BE PLACED INTO THE TRANS MISSION COVER CLOSE TO THE BEARING SEAT AND THE WOODEN SURFACE SINCE WITHOUT BELL THE ENTIRE COVER STRUC TURE WOULD BEND NOT ONLY IN THE AREA OF MAXIMUM STURDINESS Specific tooling 001467Y002 Driver for OD 73 mm bearing 020376Y Adaptor handle 020375...

Page 87: ... special tool N B PROPERLY SUPPORT THE OUTSIDE COVER TO PREVENT DAMAGING THE PAINTED SUR FACE Specific tooling 020376Y Adaptor handle 020358Y 37x40 mm adaptor 020439Y 17 mm guide Baffle roller Plastic roller Installation of belt anti vibration roller Install the anti flapping roller with the lip facing the engine crankcase Tighten the central screw to the prescribed tor que N B TURN THE DRIVEN AND...

Page 88: ...DOES NOT ROTATE FREELY REPLACE THE COMPLETE ROLLER Removing the driven pulley Remove the driven pulley assembly with the belt Inspecting the clutch drum Remove the clutch bell Check that the clutch bell is not worn or damaged Measure the clutch bell inside diameter N B CHECK THE ECCENTRICITY MEASURED 0 2 MM MAX Characteristic Max value 160 5 mm Standard value Engine Nexus 500 ENG 6 ...

Page 89: ...wn in the figure CAUTION THE TOOL SHOULD BE FIRMLY SECURED IN A VICE USING THE SPECIAL TOOL DO NOT TIGHTEN THE REAR SCREW TOO MUCH AS THIS COULD CAUSE AN IRREVERSIBLE TOOL DEFORMATION USING THE SPECIAL 55 MM WRENCH REMOVE THE FASTENING RING NUT LOOSEN THE TOOL SCREW AND DISASSEMBLE THE DRIVEN PULLEY UNIT CLUTCH SPRING WITH SHEATH Specific tooling 020444Y Tool for fitting removing the driven pulley...

Page 90: ...HREADING Specific tooling 020376Y Adaptor handle 020456Y Ø 24 mm adaptor 020363Y 20 mm guide N B IF YOU NEED TO OVERHAUL THE BEARINGS ON AN ASSEMBLED DRIVEN PULLEY UNIT IT IS NECESSARY TO SUPPORT THE UNIT BY THE BELL Specific tooling 001467Y002 Driver for OD 73 mm bearing Remove the roller bearing using the special tool supporting the fixed half pulley with the bell Specific tooling 020376Y Adapto...

Page 91: ... inside sealing rings and the 2 out side O rings Measure the movable half pulley bushing inside diameter Characteristic Maximum admissible diameter 50 08 mm Standard diameter 50 085 mm Refitting the driven half pulley bearing Install a new roller bearing using the special tool N B PLACE THE BEARING WITH THE WRITINGS AND THE EMBEDDED OIL GUARD FACING OUT WARDS Properly support the half pulley to pr...

Page 92: ...AT THE BASE OF THE HALF PULLEY Install the half pulley on the bushing being careful not to damage the top sealing ring during the in troduction Make sure the pins and collar are not worn re assemble the pins and collar Using a bent beak greaser lubricate the driven pulley unit with about 10 gr of grease this operation should be carried out through one of the two holes into the bushing to obtain th...

Page 93: ...thickness of the clutch mass friction material Characteristic Minimum thickness permitted 1 mm The masses must exhibit no traces of lubricants in that case check the driven pulley unit seals N B UPON RUNNING IN THE MASSES MUST EXHIBIT A CENTRAL CONTACT SURFACE AND MUST NOT BE DIFFERENT FROM ONE ANOTHER VARIOUS CONDITIONS CAN CAUSE THE CLUTCH TO TEAR Do not open the masses using tools to prevent a ...

Page 94: ...g the driven pulley clutch Compress the spring and insert the clutch on the driven pulley bushing N B BE CAREFUL NOT TO DAMAGE THE SHEATH OR THE BUSHING THREADED END Tighten the ring nut by hand and complete the tightening using the special wrench to the prescri bed torque Specific tooling 020444Y Tool for fitting removing the driven pulley clutch Locking torques N m Clutch ring nut 65 75 To facil...

Page 95: ...amaged Check the width of the belt Characteristic Minimum width 25 mm Standard width 26 2 mm Removing the driving pulley Using a 27 mm wrench turn the central pulley nut to horizontally align the central inside holes and install the special tool Specific tooling 020474Y Driving pulley lock wrench Nexus 500 Engine ENG 13 ...

Page 96: ...bushing connection washer Move the belt downwards Suitable support the roller contrast and extract the mobile driving half pulley with the relevant bushing and the rear washer being careful not to make the rollers come out Inspecting the rollers case Check that the inside bushings shown in the figure are not worn and measure the inside diameter CAUTION DO NOT LUBRICATE OR CLEAN THE BUSHINGS Charac...

Page 97: ...the variator back plate are not worn Check the wear of the roller housings and of the belt contact surfaces on both pulley halves Refitting the driving pulley Installing the roller container Install the spacer with the internal chamfer facing towards the inside Position the rollers on the half pulley as shown in the figure The closed side must rest on the inside thrust face of the roller container...

Page 98: ...the half pulley on the crankshaft Insert the spacer bushing Installing the fixed driving half pulley Insert the spacer Install the fixed driving half pulley and check that it is in contact with the spacer and with the guide bushing of the moving driving pulley Engine Nexus 500 ENG 16 ...

Page 99: ...E STOP WRENCH TOOL IS EASILY INSERTED INTO THE PULLEY AND IN THE ENGINE CRANKCASE Specific tooling 020474Y Driving pulley lock wrench Install the lock ring from the rear so that the splines are completely engaged Finally install the tool by siding the nuts by hand and ensuring the tool is resting flatly Tighten the driving pulley fastening nut to the prescribed torque Remove the special tool Locki...

Page 100: ...over 23 26 Lock the 7 M6 retainers Locking torques N m M6 retainer 11 13 Insert the washers on the driven pulley shaft N B INSERT THE SMALLER WASHER FIRST THEN THE LARGER ONE Insert the flanged nut Prepare the torque wrench for LHS locking using a machine hexagon wrench Tighten the driven pulley shaft fastening nut using an offset wrench N B DUE TO THE HIGH TIGHTENING TORQUE US ING DIFFERENT WRENC...

Page 101: ... EXHAUST OPENINGS ARE COMPLETELY FREE Install the outside plastic transmission cover Tighten the 4 fastening screws to the prescribed torque Locking torques N m Outside transmission cover screws 7 9 End gear Removing the hub cover Drain the rear hub oil through the oil drainage cap located under the engine Drain the rear hub oil through the oil drainage cap located under the engine Remove the 7 fa...

Page 102: ...gear shaft bearing on the engine crankcase use the following parts Specific tooling 001467Y014 Pliers to extract ø 15 mm bearings 001467Y034 Extraction pliers for ø 15 mm bear ings 001467Y031 Bell Use the special extractor to disassemble the bearing on the engine chassis of the countershaft Specific tooling 001467Y006 Pliers to extract 20 mm bearings 001467Y035 Belle for OD 47 mm bearings Engine N...

Page 103: ...67Y007 Driver for OD 54 mm bearing Removing the wheel axle bearings Take out the clip on the outside of the gearbox cover Support the hub cover using the column kit Pull out the bearing using the special tool Specific tooling 020476Y Stud bolt set 020376Y Adaptor handle 020477Y Adaptor 37 mm 020483Y 30 mm guide Remove the oil guard using a screwdriver Nexus 500 Engine ENG 21 ...

Page 104: ...e engine crankcase using the special tool Specific tooling 020376Y Adaptor handle 020358Y 37x40 mm adaptor 020364Y 25 mm guide Inspecting the hub shaft Check that the 3 shafts exhibit no wear or defor mation on the grooved surfaces at the bearings and at the oil guards In case of faults replace the damaged parts Characteristic Connection diameter for countershaft A diameter 20 0 01 0 02 mm Connect...

Page 105: ...against the bottom of the seat using the special tool N B PLACE IT WITH THE BALLS FACING THE HUB THIS APPLIES TO BEARINGS WITH PLASTIC CAGE Specific tooling 020376Y Adaptor handle 020360Y Adaptor 52 x 55 mm 020364Y 25 mm guide Heat the intermediate gear bearing seat Insert the intermediate shaft bearing using the special tool N B PLACE IT WITH THE BALLS FACING THE HUB THIS APPLIES TO BEARINGS WITH...

Page 106: ...THE BALLS FACING THE HUB THIS APPLIES TO BEARINGS WITH PLASTIC CAGE Specific tooling 020376Y Adaptor handle 020359Y 42x47 mm adaptor 020412Y 15 mm guide Place the safety lock seeger ring of the driven pulley shaft bearing N B PLACE IT IN THE POSITION SHOWN IN THE FIGURE Insert the pulley shaft oil guard on the transmis sion side Engine Nexus 500 ENG 24 ...

Page 107: ...ecial tool N B PLACE IT WITH THE BALLS FACING THE HUB THIS APPLIES TO BEARINGS WITH PLASTIC CAGE Specific tooling 020376Y Adaptor handle 020360Y Adaptor 52 x 55 mm 020363Y 20 mm guide Heat the gear shaft bearing seat from the cover outside Insert the gear shaft bearing on the cover using the special punch until abutment Specific tooling 020376Y Adaptor handle 020360Y Adaptor 52 x 55 mm 020483Y 30 ...

Page 108: ...roper position of the centring dowels Install a new gasket Fit the gearbox cover making sure the breather pipe is in the correct position Position the 7 set screws tighten them to the prescribed torque being careful of the position of the bands holding the vent tube and the position of the 3 shortest screws as indicated in the figure Refill with the prescribed oil to the Max level Recommended prod...

Page 109: ...the feed hoses and disconnect the return hose from the pump cover N B THE BANDS MUST BE REPLACED TO RE MOVE THEM OPEN WITH A SCREWDRIVER OR CUT THEM BE CAREFUL NOT TO DAMAGE THE PLASTIC UNIONS Removing the hub cover Drain the engine oil by removing the drainage cap Prepare a suitable container to collect the oil Remove the pre filter Nexus 500 Engine ENG 27 ...

Page 110: ...e support N B THE SCREWS ARE OF 4 DIFFERENT LENGTHS NOTE THE RELEVANT POSITIONS CAUTION REMOVE THE COVER AVOIDING ANY POSSIBLE INTERFERENCE BETWEEN STATOR AND ROTOR CAUTION BE CAREFUL TO PREVENT SLIPPAGE OF THE BY PASS VALVE AND OF THE RELEVANT SPRING Removing the flywheel cover components Loosen the six mounting screws and remove the water pump cover Engine Nexus 500 ENG 28 ...

Page 111: ... pump seal Removing the stator Remove the two retaining screws and the cable guide bracket Unscrew the 3 fastening screws and remove sta tor and its wiring Loosen the two retaining screws and remove the reed valve support with bulkhead Nexus 500 Engine ENG 29 ...

Page 112: ...as outlet union with the relevant O ring Remove the water pump impeller by unscrewing it from the relevant shaft N B THE THREADING IS CLOCKWISE IT IS ADVIS ABLE TO PREVENT THE SHAFT ROTATION BY INSERTING A 12 MM WRENCH INTO THE DRIVE Extract the shaft with the relevant abutment washer Engine Nexus 500 ENG 30 ...

Page 113: ...elevant gas ket Remove the sealing ring for the pump shaft lu brication using a suitably shaped tool Remove the engine oil filling cap dipstick and the check hole cover for the distribution timing Remove the minimum oil pressure sensor Nexus 500 Engine ENG 31 ...

Page 114: ...PROPRIATE PLIERS PAYING ATTENTION NOT TO CON STRICT THE HOSES BUT ALSO TAKING CARE TO TIGHTEN THE CLAMPS SUFFICIENTLY Install the pre filter again and insert the engine oil drain plug tightening to the prescribed torque Refill the engine with the prescribed type of oil Recommended products AGIP CITY HI TEC 4T Engine oil SAE 5W 40 API SL ACEA A3 JASO MA Syn thetic oil Locking torques N m Engine oil...

Page 115: ...at contains two types of cable Rigid cables close to the stator and flexible cables close to the connector Check that the winding is positioned so as not to interfere with the heads of the retaining screws Check that the mounting surface of the crankcase is not worn or deformed Check that the by pass valve seat the torque limiter and the water pump shaft are free from wear Characteristic By pass h...

Page 116: ...AT ON THE CRANKCASE Locking torques N m Stator retainers 8 10 Install the wiring guide bracket tightening the 2 screws to the prescribed torque Locking torques N m Stator cable harness guide bracket screws 3 4 Temporarily install the distribution timing check hole cover and the engine oil filling cap bar Insert the blow by recovery duct using a new O ring Tighten the screws to the prescribed torqu...

Page 117: ...E Refitting the flywheel cover components Before reassembling check that all components are perfectly clean For the cover carefully check all lubrication chan nels in particular The 3 by pass channels Oil feeding duct at the water pump shaft connec tion Pump drainage duct Nexus 500 Engine ENG 35 ...

Page 118: ...crews to the prescribed torque Locking torques N m Supporting screws with bulkhead 0 3 0 4 Install a new sealing ring for the pump shaft using the special tool Install the oil minimum pressure sensor and tight en to the prescribed torque Specific tooling 020376Y Adaptor handle 020412Y 15 mm guide Locking torques N m Minimum oil pressure sensor 12 14 Engine Nexus 500 ENG 36 ...

Page 119: ...cating the flywheel cover seat Insert the mechanical seal on the shaft up to the impeller abutment surface N B THE FINAL INTRODUCTION DEPTH WILL BE DETERMINED BY THE IMPELLER Screw the impeller and tighten to the prescribed torque Locking torques N m Water pump impeller 4 5 Refitting the flywheel cover Lubricate the intermediate gear seat with torque limiter on the flywheel cover Align the water p...

Page 120: ...PARATION IS USEFUL PARTICU LARLY IN THE EVENT OF REPAIRS WITH THE WATER PUMP COVER INSTALLED Install the flywheel cover on the engine paying attention to avoid interference between the stator and rotor WARNING FAILURE TO OBSERVE THIS INSTRUCTION MAY RESULT IN DESTRUCTION OF THE CERAMIC MAGNETS Tighten the 14 retaining bolts of the cover to the prescribed torque N B THE BOLTS HAVE FOUR LENGTHS THE ...

Page 121: ...pped with freewheel coaxial to the flywheel and torque limiter on the intermediate shaft The limiter is calibrated to 10 kgm 100 Nm this component protects the structure of the engine and the starter kinematic mechanism in the event of incorrect starting with consequent inverse rotations The freewheel is used for a sufficiently silent starting The starter control energised remote control is slaved...

Page 122: ...nostic tester see chapter Injection system Connect the induction clamp of an ammeter to the positive power supply cable of the starter motor Remove the 10A fuse no 12 see fuses chapter Switch in position ON with interrupt switch in position RUN and side stand raised Select the PARAMETERS function Start the engine so that it cannot move long enough to measure the rpm and starter absorption N B THE ...

Page 123: ...sible melting of the bushes and if no anomalies are found replace the starter motor 8 Low trailing speed Low electrical absorption Repeat the test bridging the power terminals of the starter remote control switch or even better replacing them Check the new values YES go to 12 NO go to 13 9 High trailing speed Low electrical absorption The engine turns too freely check the compression end pressure ...

Page 124: ...BE REPLACED TO RE MOVE THEM OPEN WITH A SCREWDRIVER OR CUT THEM BE CAREFUL NOT TO DAMAGE THE PLASTIC UNIONS Removing the starter motor N B THIS OPERATION MAY ALSO BE CARRIED OUT WITH FLYWHEEL COVER ASSEMBLED Loosen the two fastening screws Extract the complete starter motor Removing the flywheel magneto N B IF YOU MUST REMOVE THE FLYWHEEL IT IS NECESSARY TO REMOVE THE CHAIN GUIDE SLIDING BLOCK RET...

Page 125: ...ng tool threading Insert the special tool as shown in the figure making sure that the pins are perfectly inserted in to the previously aligned holes and that it is per fectly abutted and almost flush with the flywheel Specific tooling 020472Y Flywheel lock wrench Loosen the magneto flywheel fastening nut Remove the special tool and the fastening nut Nexus 500 Engine ENG 43 ...

Page 126: ...ONGLY LOCKED THE CONE DETACHMENT MAY THEREFORE CAUSE THE ROTOR SLIPPAGE WITH THE CONSEQUENT BREAKAGE OF THE MAGNETS Insert the special removing tool Using a 27 mm wrench and a 19 mm bushing release the flywheel Specific tooling 020467Y Flywheel extractor Remove the extractor Remove the nut and extract the flywheel with the start up rim Remove the crankshaft key Engine Nexus 500 ENG 44 ...

Page 127: ...E THE FREEWHEEL MUST BE REMOVED IT IS ADVISABLE TO LOOSEN THE 6 FASTEN ING SCREWS IN ADVANCE WITH THE FLY WHEEL STILL INSTALLED ON THE CRANK SHAFT The freewheel is coupled to the flywheel with high precision if removal is difficult use 2 screws as gripping points and as removing tools if required Extract the intermediate gear provided with tor que limiter Nexus 500 Engine ENG 45 ...

Page 128: ... Characteristic Hub outside diameter Diameter 45 665 0 008 0 005 mm Check the inside diameter of the bushing of the starter gearing Check that the toothing is not worn Characteristic Inside diameter of the bushing Diameter 27 0 020 0 041 mm N B IF THE FAULTS DISCOVERED AFFECT THE HUB REPLACE THE STARTER RING GEAR AND FREEWHEEL IF ONLY THE BUSHING IS WORN IT IS POSSIBLE TO REPLACE ONLY THE COMPLETE...

Page 129: ...ooved profiles this assembly allows transmitting torque lower than 10 kgm In case of incorrect start up manoeuvres the lim iter prevents any kicks with consequent reversal of direction of the crankshaft which would impair the engine structure The limiter assembly cannot be overhauled In case of irregularities on the toothed discs replace the assembly Refitting the free wheel Make sure the freewhee...

Page 130: ... e with wheel Seeger ring visible Lock the six clamping screws in criss cross fash ion to the prescribed torque Locking torques N m Screw fixing freewheel to flywheel 13 15 Oil the free wheel rollers Refitting the intermediate gear Lubricate the gear housing on the engine crank case Insert the intermediate gear with torque limiter Engine Nexus 500 ENG 48 ...

Page 131: ...heel turning it clockwise and inserting at the same time Refitting the flywheel magneto Insert the key on the crankshaft Install the flywheel checking the proper insertion of the key and engaging the torque limiter gear with the start up rim Insert washer and nut on the crankshaft Nexus 500 Engine ENG 49 ...

Page 132: ...020472Y Flywheel lock wrench Align the 2 holes of the flywheel with the case housing to allow the introduction of the special tool Insert the special tool checking that the pins are perfectly introduced into the seat Specific tooling 020472Y Flywheel lock wrench Tighten the flywheel lock nut to the prescribed torque Locking torques N m Flywheel fixing nut 115 125 Engine Nexus 500 ENG 50 ...

Page 133: ... m Chain guide sliding block retain plate fasten ing screws 3 4 Refitting the starter motor Check that the O ring is in good working order and lubricate it Insert the starter motor Tighten the 2 fastening screws to the prescribed torque Locking torques N m Starter motor screws 11 13 Cylinder assy and timing system Remove the external and internal transmission cover Remove the flywheel cover the fl...

Page 134: ...cker arms cover Loosen the 6 special screws with stop and the relevant rubber gaskets Remove the tappet cover with relevant gasket Removing the timing system drive Turn the engine to close the intake valves i e moving the reference on the tone wheel to the top as shown in the figure Engine Nexus 500 ENG 52 ...

Page 135: ... and the valve lifting mass with relevant travel end washer N B BE CAREFUL NOT TO ALLOW THE WASHER AND SPRING TO FALL INTO THE ENGINE THROUGH THE CHAIN COMPARTMENT Align the references located on the tone wheel and on the head Loosen the central screw on the tensioner first Unscrew the 2 fastening screws and remove the tensioner with relevant gasket Nexus 500 Engine ENG 53 ...

Page 136: ... camshaft Remove the timing belt rim Remove the tone wheel Remove the engine revolution timing sensor and relevant O ring by loosening the fastening screw and removing the mounting band from the special hole obtained on the head gasket N B TO CHECK THIS COMPONENT SEE THE IN JECTION CHAPTER Engine Nexus 500 ENG 54 ...

Page 137: ...EWS MAY BE DIFFICULT BE CAREFUL NOT TO DAM AGE THE INSIDE HEXAGON IF NECESSARY SEPARATE THE THREADS IN ADVANCE Remove the cam shaft Remove pins and rocking levers by the transmis sion side holes Removing the cylinder head Remove the spark plug Remove the cooling system outlet sleeve with thermostat Nexus 500 Engine ENG 55 ...

Page 138: ... on the spark plug side with the thermostat support N B THE HEAD MAY BE REMOVED WITH THE CAMSHAFT ROCKING LEVER PINS AND FITTING BRACKET IF NECESSARY Loosen the 4 head cylinder fastening nuts in 2 or 3 times and in a crossed sequence Remove the head the 2 centring dowels the gasket and the lower chain guide sliding block N B DO NOT REMOVE THE DOWELS IF THEY ARE FORCED INTO THEIR SEAT CAUTION WHEN ...

Page 139: ...tool 020382Y012 bush valve removing tool CAUTION ARRANGE THE VALVES SO AS TO RECOGNISE THE ORIGINAL POSITION ON THE HEAD FLY WHEEL SIDE AND TRANSMISSION SIDE Remove the oil guards using the special tool Specific tooling 020431Y Valve oil seal extractor Remove the spring supports N B BLOW THE SEATS WITH COMPRESSED AIR TO FACILITATE THE SPRING SUPPORT RE MOVAL Nexus 500 Engine ENG 57 ...

Page 140: ...CYLINDER CAUTION TO PREVENT DAMAGES TO THE PISTON SUPPORT IT WHILE REMOVING THE CYLIN DER Remove the 2 piston pin locking rings by the spe cific housings Extract the pin and remove the piston N B USE PAPER OR A CLOTH TO CLOSE THE CYL INDER HOUSING MOUTH ON THE CRANK CASE TO PREVENT SLIPPAGE OF ONE OF THE PIN LOCKING RINGS INTO THE CASE Remove the piston sealing rings and the oil scra per CAUTION N...

Page 141: ...IN CHAPTER CRANKCASE AND CRANKSHAFT Characteristic Standard diameter 22 0 025 0 015 mm Inspecting the wrist pin Check the pin outside diameter using a micrometer Characteristic Standard diameter 22 0 0 004 mm Calculate the coupling clearance between pin and connecting rod end Characteristic Standard clearance 0 015 0 029 mm Measure the capacity diameter on the piston Characteristic Standard diamet...

Page 142: ...hown in the figure Characteristic A 43 2 mm Piston diameter 92 mm Using a bore meter measure the inner cylinder diameter at three different points according to the directions shown in the figure Characteristic Standard diameter 92 0 018 0 010 mm Check that coating is free from flakes Check that the head matching surface exhibits no deformations or wear Characteristic Maximum allowable run out 0 05...

Page 143: ...e 2 5 0 03 mm Inspecting the piston rings Alternately insert the three sealing rings into the cylinder in the area where it retains its original di ameter Using the piston insert the rings perpen dicularly to the cylinder axis Measure the opening see figure of the sealing rings using a feeler gauge If higher values than those prescribed are meas ured replace the linings N B BEFORE REPLACING ONLY T...

Page 144: ... with the opening in the position indicated on the tool S left D right Place the wrist pin stop ring into position using a punch Install the pin lock using the key shown in the figure Specific tooling 020470Y Pin retainers installation tool N B THE TOOL FOR INSTALLING THE STOP RINGS MUST BE USED MANUALLY CAUTION USING A HAMMER MIGHT DAMAGE THE STOPS HOUSING Engine Nexus 500 ENG 62 ...

Page 145: ...t until TDC the inverted point of the dial gauge rotation Measure the deviation from the reset value Identify the thickness of the cylinder base gasket to be used for reassembly by the table below Cor rectly identify the cylinder base gasket thickness to keep the correct compression ratio Remove the special tool and the cylinder N B IF DEVIATIONS OR RECESSES OR PROJECTIONS CLOSE TO THE CHANGE OF C...

Page 146: ...ed by the housing It is advisable to use a fitter to facilitate the in stallation of the linings N B THE TWO PISTON RINGS ARE MADE WITH A TAPERED CYLINDRICAL CONTACT CROSS SECTION THIS IS TO ACHIEVE A BETTER BEDDING Misalign the lining openings at 120 as shown in the figure Lubricate the components with engine oil The engine uses the first compression lining with an L section Refitting the cylinde...

Page 147: ...the coolant sealing pad exhibits no oxidation STANDARD DIAMETER Specification Desc Quantity A 13 0 018 0 B 20 0 021 0 C 42 0 025 0 If wear is discovered replace the head and check also the corresponding component Inspecting the timing system components Check that the guide shoe and the tensioner shoe are not worn out Check that the crankshaft pinion and the cam shaft timing gear and crankshaft pin...

Page 148: ...r head Alternatively check the intake and exhaust valves The test is carried out by filling the manifold with petrol and checking that the head does not ooze through the valves when these are just pressed with the fingers Visually inspect the valve sealing surface CAUTION DO NOT REVERSE THE FITTING POSITIONS OF THE VALVES RIGHT LEFT If the sealing surface of the valve is found to be interrupted at...

Page 149: ...6 mm If the impression width on the valve seat is larger than the prescribed limits true the seats with a 45 mill and then grind In case of excessive wear or damages replace the head Inspecting the valves Measure the diameter of the valve stems in the three positions indicated in the diagram STANDARD DIAMETER Specification Desc Quantity Inlet 4 987 4 972 mm Outlet 4 975 4 960 mm MINIMUM ADMISSIBLE...

Page 150: ...relative to the valve head and rotate it on a V shaped abutment Characteristic Admissible limit 0 03 mm Inspecting the valve stem guide clearance After measuring the valve guide diameter and the valve stem diameter check the clearance between guide and stem INLET Specification Desc Quantity Standard clearance 0 013 0 04 mm Admissible limit 0 08 mm OUTLET Specification Desc Quantity Standard cleara...

Page 151: ...der head with the valve ax es in a horizontal position This will prevent the lapping compound residues from penetrating be tween the valve stem and the guide see figure CAUTION TO AVOID SCORING THE CONTACT SURFACE DO NOT KEEP ROTATING THE VALVE WHEN NO LAPPING COMPOUND IS LEFT CAREFULLY WASH THE CYLINDER HEAD AND THE VALVES WITH A SUITABLE PRODUCT FOR THE TYPE OF LAPPING COMPOUND BEING USED CAUTIO...

Page 152: ...ng the appropriate tool with adapter compress the springs and insert the cotters in their seats Specific tooling 020382Y Valve cotters equipped with part 012 removal tool 020382Y012 bush valve removing tool N B DO NOT CHANGE THE VALVE FITTING POSITION FIT THE VALVE SPRINGS WITH THE REF ERENCE COLOUR ON COTTER SIDE TURNS WITH GREATER PITCH Inspecting the cam shaft Check that the camshaft ends exhib...

Page 153: ...40 mm Using a gauge measure the cam height STANDARD HEIGHT Specification Desc Quantity Intake 33 988 mm Exhaust 33 417 mm ADMISSIBLE LIMITS Specification Desc Quantity Intake 33 740 mm Exhaust 33 170 mm Standard axial clearance 0 0 22 mm Maximum admissible axial clearance 0 3 mm Nexus 500 Engine ENG 71 ...

Page 154: ...butment on the containment bell are free from wear Check that the valve lifting spring has not yielded Replace any defective or worn components Check that the rocking lever pins exhibit no scores or wear Characteristic Standard diameter 13 0 010 0 018 mm Measure the inside diameter of each rocking lever Characteristic Standard diameter 13 0 026 0 015 mm Check that the cam contact sliding block and...

Page 155: ...THE DOWELS The head gasket is made of steel and has a standard thickness Check that the head lubrication channel is per fectly clean Clean with compressed air jets if required Insert the head Lubricate the stud bolts and the 4 fixing stud bolts Tighten the 4 fastening columns crosswise to the prescribed torque as shown in the figure Tighten the 4 screws by 90 in the sequence shown in the figure Fu...

Page 156: ... TORQUE CAN DAMAGE THE SENSOR Locking torques N m coolant temperature sensor 10 12 Install the spark plug and tighten to the prescribed torque Locking torques N m Spark plug 12 14 Insert the timing control belt on the crankshaft according to the initial direction of rotation Install the tensioner shoe with its spacer tight ening the bolt to the prescribed torque using the recommended product Recom...

Page 157: ...sidues from the screws fixing the camshaft retaining bracket using a brush Apply the recommended product to the fixing screws and tighten the screws after wiping off any threadlock deposits Recommended products Loctite 243 Medium strength threadlock Loctite 243 medium strength threadlock Insert the camshaft retain bracket with visible countersinks and tighten the 3 fastening screws to the prescrib...

Page 158: ...ing it as shown in the figure Tighten the 2 fastening screws to the prescribed torque N B TO CHECK THIS COMPONENT SEE CHAPTER INJECTION Locking torques N m Rpm timing sensor fixing screw 3 4 Install the intermediate gear with torque limiter the flywheel and its cover as described in Chapter Flywheel and start up system and in Chapter Flywheel cover N B FOR MORE CONVENIENCE INSTALL THE FLYWHEEL COV...

Page 159: ...rank shaft using the driving pulley to make the reference on the magnet support collimate with that on the flywheel cover Insert the belt on the camshaft control timing rim Insert the timing rim on the camshaft checking that the references are aligned N B DURING THE STROKE CHECK KEEP THE BELT TENSIONED BY PRESSING ON THE TIGHTENER COMPARTMENT SIDE Nexus 500 Engine ENG 77 ...

Page 160: ...ll the valve lifting mass being careful to the proper positioning of the travel end ring Lubricate the mass and de compressor control pin Install the return spring and load it by about 3 4 turn Turn the engine to move the references to the top as shown in the figure intake end Insert the valve lifting device mass stop bell Tighten the retaining screw to the prescribed torque using the recommended ...

Page 161: ...lues are found adjust by loos ening the lock nut and use a screwdriver for the set screw as shown in the figure Refitting the timing chain The ignition advance is determined electronically on the basis of parameters known by the control unit For this reason it is not possible to declare the reference values based on the engine rpm The ignition timing value is detectable any time using the diagnost...

Page 162: ...er Remove the TDC reference inspection cap be tween flywheel and crankcase cover See the fly wheel cover chapter By the driving pulley turn the engine to find the alignment of the references to identify the TDC Repeat for the reference between driving pulley and transmission housing Engine Nexus 500 ENG 80 ...

Page 163: ...asured using the diag nostic tester Specific tooling 020460Y Scooter diagnosis and tester If the values do not match check distribution timing revolution timing sensor Injection control unit This section described the operations to be carried out on the manifold components Inspecting the radial air gap Align a tooth of the tone wheel with the revolution timing sensor Check the air gap using a prob...

Page 164: ... two fastening screws to the prescri bed torque Locking torques N m Tightener fastening screws 11 13 Insert the spring with the central screw and the washer Tighten the central screw to the prescribed tor que Locking torques N m Tightener screw 5 6 Refitting the rocker arms cover Check that the gasket is in good working order Engine Nexus 500 ENG 82 ...

Page 165: ...he transmission cover and the relevant net filter and the outside transmission cover as descri bed in the Automatic transmission chapter Install the cooling system sleeves using new bands as described in the Flywheel cover chap ter Refitting the intake manifold Install the intake manifold on the engine Insert the 3 fastening screws one of which with a support band for the cooling system sleeve and...

Page 166: ...n Remove the flywheel cover with the cooling sys tem sleeves as described in the Flywheel cover chapter Remove the flywheel with the starting system fol lowing the instruction given in Flywheel and Start ing system Remove the thermal unit cylinder head piston as described in the Thermal unit and timing system chapter Engine Nexus 500 ENG 84 ...

Page 167: ...for dial gauge Characteristic Standard clearance 0 10 0 50 mm Admissible increase limit after use 0 60 mm Upper clearances are an indication of wear on the surfaces of the crankshaft casing support To carry out an accurate measurement measure the clearance in both directions between crankcase and crankshaft Splitting the crankcase halves Remove the engine support retain screw on the flywheel side ...

Page 168: ... the crankshaft check the timing with the countershaft To carry out this check turn the crankshaft to align the two holes obtained on the crankshaft with the hole on the countershaft control gear This is an optimal position also to remove the crankshaft Remove the crankshaft with the shim adjustment washer on the flywheel side CAUTION WHILE OPENING THE CRANKCASE AND RE MOVING THE CRANKSHAFT CHECK ...

Page 169: ... IS LOCKED BY LOC TITE BE CAREFUL NOT TO DAMAGE THE CONTROL HEXAGON TO OBTAIN BETTER RESULTS IT IS PREFERABLE TO USE AN IN SIDE HEXAGON SOCKET WRENCH Removing the countershaft Place the special tool as shown in the figure Specific tooling 020479Y Countershaft lock wrench Remove the fastening nut with relevant washer Remove the special tool and extract the counter shaft with the control gear Nexus ...

Page 170: ... tool and a mallet Specific tooling 020376Y Adaptor handle 020358Y 37x40 mm adaptor 020439Y 17 mm guide Remove the bearing from the transmission side half crankcase using the special tool Specific tooling 001467Y008 Pliers to extract 17 mm ø bearings 001467Y007 Driver for OD 54 mm bearing Before installing a new bearing heat the flywheel side half crankcase using the special tool Place the half cr...

Page 171: ...m adaptor 020439Y 17 mm guide Fit the seeger ring Before installing the new bearing on the trans mission side crankcase heat the seat using the special tool Specific tooling 020151Y Air heater Insert a new bearing on the special tool after greasing the guide seat Install the new bearing on the engine crankcase using the special tool N B IF A BEARING WITH PLASTIC CAGE IS USED KEEP THE BALLS VISIBLE...

Page 172: ...he axial free play are not scored and measure the width of the crank shaft between these surfaces as shown in the diagram N B BE CAREFUL NOT TO LET THE MEASURE MENT BE AFFECTED BY THE UNIONS WITH THE CRANKSHAFT ENDS Characteristic Standard dimensions 63 6 63 45 mm CAUTION THE CRANKSHAFT CAN BE REUSED WHEN THE WIDTH FALLS WITHIN THE STANDARD VALUES AND THE SURFACES ARE FREE FROM SCRATCHES Shimming ...

Page 173: ...ne crankcase Check the diameters of both the bearings of the crankshaft in accordance with the axes and surfa ces shown in the figure Half shafts are classified into two categories Cat 1 and Cat 2 STANDARD DIAMETER Specification Desc Quantity Cat 1 40 010 40 016 Cat 2 40 016 40 022 Inspecting the crankshaft alignment Install the crankshaft on the support and measure the displacement at the 4 point...

Page 174: ...N B IN CASE OF REPLACEMENT OF A CRANKSHAFT CONSISTING OF TWO HALF SHAFTS OF DIF FERENT CATEGORY REPLACE THE TWO HALF CRANKCASES AS WELL COUPLING THE TWO COMPONENTS SHAFT AND CRANKCASE WITH THE SAME CATEGORY To check the gearing of the crankshaft see sec tion Thermal unit and timing system See also Cylinder assy and timing system Inspecting the crankcase halves Before proceeding to check the crankc...

Page 175: ...ICATION PRESSURE ADJUSTMENT PISTON THE HEAD LUBRICATION CHANNEL IS PROVIDED WITH A SHUTTER JET THIS GIVES A LOW PRESSURE HEAD LUBRICA TION THIS CHOICE WAS MADE TO REDUCE THE OIL TEMPERATURE IN THE SUMP The jet clogging impairs the head lubrication and the timing mechanisms A jet failure causes a decrease of the main bearing and connecting rod lubrication pressure Check that the surfaces are free f...

Page 176: ...compared with the crankshaft axial clearance of the limiting surface N B TO KEEP THE BUSHINGS ON THE CRANKCASE IN SUCH POSITION DRIVING IS FORCED ON CAST IRON RINGS INSERTED IN THE CASTING OF BOTH CRANKCASE HALVES Check the inside diameter of the main bushings in the three directions indicated in the diagram Repeat the measurements for the other bushing half see diagram N B DO NOT TAKE THE MEASURE...

Page 177: ...ategories Spare shafts have half shafts of the same category N B TO REPLACE THE HALF SHAFTS REMOVE THE COUNTERSHAFT BEARINGS AS DESCRIBED ABOVE REMOVE THE COMPLETE DRIVEN PULLEY AND THE ANTI FLAPPING ROLLER FROM THE TRANSMISSION SIDE HALF CRANKCASE AS DESCRIBED IN CHAPTER AUTOMATIC TRANSMISSION AND THE HUB COVER WITH THE RELEVANT GEARS AND BEARINGS AS DESCRIBED IN CHAPTER FINAL REDUCTION Countersh...

Page 178: ...e 4 fastening screws Insert the control gear on the crankshaft with the hole countersink visible Tighten the 4 fastening screws to the prescribed torque N B TO AVOID DAMAGING THE SCREW CONTROL HEXAGON IT IS PREFERABLE TO USE AN IN SIDE HEXAGON SOCKET WRENCH Locking torques N m Gear mounting on crankshaft screws 10 12 Lubricate the main bearing on the flywheel side half crankcase Lubricate the shim...

Page 179: ... Install the oil pump closing plate Tighten the 2 flanged fastening screws to the prescribed torque Locking torques N m Bulkhead screws for oil pump housing cover 8 10 Refitting the crankcase halves Remove the oil guard from the transmission side half crankcase using a screwdriver Install a new oil guard after lubricating it using the special tool arranging it at a 0 5 mm recess from the crankcase...

Page 180: ... crankcase without tightening Insert the 14 fastening screws by arranging the single shorter screw A and the single longer screw B as shown in the figure Tighten the screws thoroughly and tighten to the prescribed torque Check that the crankshaft rotates freely N B REMOVE ANY EXCESS FROM THE CRANKCASE COUPLING GASKET ON THE CYLINDER PLANE TO ENSURE BETTER SEALING PERFORMANCE Locking torques N m En...

Page 181: ... and the relevant mesh filter and the outside transmission cover as described in the section Automatic transmission See also Cylinder assy and timing system Flywheel cover Lubrication TECHNICAL SPECIFICATIONS SUMP CAPACITY Specification Desc Quantity Overhaul 1 7 l Oil and filter replacement 1 5 l RECOMMENDED ENGINE OIL Product Description Specifications AGIP CITY HI TEC 4T Engine oil SAE 5W 40 AP...

Page 182: ...ER Specification Desc Quantity Type mesh plastic OIL FILTER Specification Desc Quantity Type Paper with pressure relief and anti drain back by pass valves OIL MINIMUM PRESSURE INDICATOR LIGHT SWITCH Specification Desc Quantity Calibration 0 3 0 6 bar HEAD LUBRICATION CONTROL JET Specification Desc Quantity Diameter 1 0 05 mm Tightening torque 5 7 N m PISTON COOLING NOZZLE Specification Desc Quanti...

Page 183: ...ristics Lubrication circuit is split into two sections High pressure Low pressure The high pressure section includes all components located on the engine crankcase while the low pressure section only refers to the thermal unit The trochoidal pump is installed into the sump and is controlled through a couple of gears To guarantee the integrity of the pump a pre filter is installed The pre filter is...

Page 184: ...amshaft is partly compensated by the oil supplied to the small end bearings The camshaft supplies the lubricant to the rocking levers via the bores provided these are installed in a position to ensure that the lubrication is maintained even after the scooter has stopped This is ach ieved when the camshaft reaches its most usual and likely position when the engine is switched off The oil used to lu...

Page 185: ...ontact with the crankcase bottom and pull back a few millimetres Specific tooling 020331Y Digital multimeter AHEAD go to 5 5 Measure the pressure with cold and idling engine STANDARD VALUES Specification Desc Quantity 20 C Temperature 1400 rpm approx 4 5 bar N B RPM CAN BE MEASURED BOTH BY THE EXHAUST GAS ANALYSER AND BY THE DIAGNOSTIC TESTER Specific tooling 020460Y Scooter diagnosis and tester Y...

Page 186: ...on of rotation with the connecting rod in quadrature YES go to 16 NO go to 17 15 Replace the faulty components Flywheel cover chapter 16 Overhaul the engine Crankcase and crankshaft chapter 17 Open the engine crankcase and remove the oil pump as described in the Crankcase and crank shaft chapter Check the oil pump as described in the following pages Check that the cooling nozzle and the timing fee...

Page 187: ...HIGHER VISCOSITY CAUSES AN INCREASE OF THE SYSTEM PRESSURE 1 If oil consumption is above 250 g 1000 km on a run in engine proceed as follows AHEAD go to 2 2 Check the presence of oil at the scavenge duct on the filter box YES go to 3 NO go to 4 3 Check the one way reed valve and the decantation chamber drainage hole YES go to 5 NO go to 4 4 Check the thermal group seals piston rings valve guides a...

Page 188: ...ning the 2 retaining screws through the eyes machined in the gearing proper Remove the gasket Remove the two screws and the oil pump cover Remove the inside rotor retaining snap ring turn ing it to move the opening at the shaft face Engine Nexus 500 ENG 106 ...

Page 189: ...the shaft with the gear and install the lock ring then turn it with the opening opposed to the shaft face Check any irregular clearance between shaft and pump body Using a thickness gauge check the distance be tween the rotors in the position shown in the figure Characteristic Admissible limit clearance 0 012 mm Check the distance between outside rotor and pump body see figure Characteristic Admis...

Page 190: ...oil pump see the Lubrication chapter Refitting Make sure the gasket is in the correct position N B THE TOOTH OF THE GASKET MUST BE IN ITS SEAT Insert the oil pump with gear Insert the 2 retaining screws through the slots on the gear and tighten to the prescribed torque N B THE ASSEMBLY POSITION OF THE PUMP IS FIXED BY INSTALLATION OF THE SCREWS Engine Nexus 500 ENG 108 ...

Page 191: ...with the nut Tighten the nut to the prescribed torque using the recommended product Remove the special tool Recommended products Loctite 243 Medium strength threadlock Loctite 243 medium strength threadlock Locking torques N m Countershaft fixing nut 25 29 Lubricate the internal rotors Check there are no signs of scoring or wear on the oil pump cover If non conforming values or signs of wear are f...

Page 192: ...Oil pump cover screws 0 7 0 9 Engine Nexus 500 ENG 110 ...

Page 193: ...INDEX OF TOPICS INJECTION INJEC ...

Page 194: ...l switch The electric fan system is powered by a remote control switch connected to the continuous power supply controlled by the electronic control unit of the injection system The electronic control unit of the injection system controls the electric fan in relation to the measured engine temperature If prolonged running of the electric fan is noticed check the following carefully before starting...

Page 195: ...Activate the electric fan diagnostic func tion Check acoustically for rotation of the electric fan Wait for the exit from the diagnostic tester YES go to 3 NO go to 4 3 Test successful The fan is rotating YES go to 5 4 Test failed The fan is not rotating YES go to 8 NO go to 6 5 The electric fan system is OK 6 Test successful The fan is not functioning YES go to 7 7 The remote control switch circu...

Page 196: ...eck for continuity between pin 86 of the remote control switch connector and pin 5 of the electronic control unit 86 green white 5 0Ω continuity YES go to 14 NO go to15 14 Check the earth insulation 5 23 1 MΩ infinite YES go to 16 NO go to 15 15 Repair or replace the cable harness 16 Connect the remote control switch and check for battery voltage between terminals 5 and 23 with the key switch in p...

Page 197: ...ir does not infiltrate Specific tooling 020623Y Pre service gas extraction set Check the exhaust emissions from the muffler after the catalytic converter with the engine warm and idling STANDARD VALUES WITH THE ENGINE IDLING Specification Desc Quantity CO di XXX CO2 di XXX HC di XXX ppm O2 XXX Lambda factor XX If the values measured are the same as those obtained with what was collected from the e...

Page 198: ...nalyser Remove the exhaust manifold cover and connect the extension to the coupling clamp for the analy ser pipe YES go to 3 3 Connect the diagnostic tester Set the switch to ON with switch to RUN and side stand raised YES go to 4 4 Select the menu on the ERRORS function Check whether there are any failures YES go to 6 NO go to 5 5 Select the menu on the PARAMETERS func tion YES go to 7 6 Repair a...

Page 199: ...The numbers displayed can be positive or nega tive YES go to 13 13 â To increase the CO the injection time needs to be increased To decrease the CO the injection time needs to be decreased Adjust the trimmer value according to the indications in the table YES go to 14 TRIMMER VALUE 100 50 10 0 10 50 100 INJECTION TIME HIGH Ã LOW Ã MEDIUM C O INCREASE Ã Ã DECREASE N B THE TRIMMER VALUE 0 CORRESPOND...

Page 200: ...k plug valve clearance timing system phase outlet valves for sealing When the control unit is replaced reset TPS and pre program the trimmer value of the original control unit if available preventively In any case check the CO value again N B WHEN THE CO PERCENTAGE IS RIGHT AND THE CO2 PERCENTAGE DOES NOT FALL INTO THE SPECIFIED VALUES THE LAMBDA VALUE IS ALSO DISTORTED If this occurs carefully ch...

Page 201: ...ion is managed by modifying the injector opening time The fuel feed pressure is held steady in accordance with the environmental pressure The feed circuit consists of Fuel pump Fuel filter Injector Pressure regulator Pump filter and regulator are placed into the fuel tank using a single support The injector is connected by two pipes provided with quick couplings This allows obtaining a continuous ...

Page 202: ...onger present the data storage is automatically cleared after 16 cycles of use cold start running at regular engine temperature stop The diagnostic tester is also required to adjust the idle mixture Specific tooling 020460Y Scooter diagnosis and tester The EMS injection ignition system has a control function over the rpm indicator and the radiator cooling electric fan The EMS is connected to the a...

Page 203: ... expected to remain unused for a long time refill the tank up to a little over half the level This will ensure the pump will be covered by fuel 7 When washing the vehicle be careful with the electric components and wiring 8 When an ignition problem is detected start the checks from the battery and the injection system connections 9 Before disconnecting the EMS control unit connector perform the fo...

Page 204: ...ator consumption counter 4 Engine temperature 5 86 electric fan remote control switch 6 Stepper motor Stepper motor 7 Engine rpm sensor 8 9 EMS diagnostic connector 10 EMS diagnostic connector 11 Throttle potentiometer signal 12 Engine rpm sensor 13 Injector control negative 14 Stepper motor Stepper motor 15 Instrument panel injection warning light negative 16 Decoder serial Overturn sensor 17 Bas...

Page 205: ...epper motor Stepper motor 25 26 Continuous power supply positive IMMOBILIZER DECODER Specification Desc Quantity 1 2 Immobilizer LED control negative 3 Base power supply positive 4 Negative 5 6 Electronic control unit EMS serial 7 8 Continuous power supply positive Immobilizer aerial Nexus 500 Injection INJEC 13 ...

Page 206: ... temperature sensor 10 Throttle potentiometer 11 Stepper motor Stepper motor 12 Electronic control unit EMS serial 13 Immobilizer aerial 14 Decoder 15 EMS diagnostic socket 16 Stroke revolution sensor 17 Stand switch 18 Emergency stop switch 19 Diode 2 A 20 Fuse 3 A 21 Engine stop remote control switch 22 Main remote control switch 23 Key switch 24 Rectifier regulator 25 Fuse 10 A 26 Fuse 30A Inje...

Page 207: ...w Power to the spark plug Shielded spark plug cap HV coil secondary insu lation Parameter reliability Coolant temperature Distribution timing injection ignition Intake air temperature End of compression pressure End of compression pressure Starting difficulties ENGINE START UP PROBLEMS Possible Cause Operation Presence of faults detected by the self diagnosis Pump relay H V coil Injector revolutio...

Page 208: ...ters Throttle valve position sensor Stepper Coolant temperature sensor Intake air temperature sensor Intake system cleaning Air filter Diffuser and throttle valve Additional air pipe and Stepper Intake system sealing infiltrations Intake manifold head Throttle body manifold Intake sleeve Filter box Fuel feed low pressure Fuel pump Pressure regulator Fuel filter Injector capacity Analysis of exhaus...

Page 209: ...tor revolution timing sensor Air temperature Coolant temperature Atmospheric pressure Correctness of the parameters Throttle valve position sensor Stepper Coolant temperature sensor Intake air temperature sensor Intake system sealing infiltrations Intake manifold head Throttle body manifold Intake sleeve Filter box Fuel feed low pressure Fuel pump Pressure regulator Fuel filter Injector capacity E...

Page 210: ...con verter Trimmer value adjustment CO adjustment Poor performance at full throttle POOR ENGINE PERFORMANCE AT FULL POWER IRREGULAR ENGINE PROGRESS ON PICKUP Possible Cause Operation Presence of faults detected by the self diagnosis Pump relay H V coil Injector revolution timing sensor Air temperature Coolant temperature Atmospheric pressure Spark plug power supply Spark plug Shielded cap HV cable...

Page 211: ...njector capacity Fuel quality Selection of the cylinder base gasket thickness Selection of the cylinder base gasket thickness Decoder master box circuit This section describes the operations to be carried out to check the power supply circuit Constant supply circuit check The decoder basic power supply is necessary for the deterrent flashing management The injection control unit power supply is ne...

Page 212: ...switch to RUN The injec tion warning light comes on for about 5 seconds YES go to 6 NO go to 7 6 The injection controller is certainly powered 7 Check the efficiency of the 3 A fuse no 3 loca ted in the fuse holder under the right side YES go to 10 NO go to 8 8 Fix any wiring short circuits and replace the fuse YES go to 1 NO go to 9 9 Check any short circuit on decoder or control unit and replace...

Page 213: ...l and on pin 3 of the decoder connector YES go to 12 NO go to 14 YES go to 11 14 Fix the cable harness Key switch power supply circuit check A failure of the constant power supply disables both ignition and injection functions In case of power supply faults the diagnostic tester gives the information NO REPLY FROM THE CONTROL UNIT Specific tooling 020460Y Scooter diagnosis and tester 1 Check wheth...

Page 214: ...t if necessary YES go to 1 7 Disconnect the main decoder connector and check the following conditions switch set to ON switch to RUN and side stand raised Terminal no 8 battery positive Terminal no 4 battery negative YES go to 8 NO go to 10 8 Decoder with proper continuous power supply Use the special tool to check the control unit con tinuous power supply Switch set to ON switch to RUN and side s...

Page 215: ...set to ON Pin 1 2 continuity YES go to 14 14 Check the engine stop remote control switch connector and the switch efficiency The connector can be recognised by its larger sec tion white lead 85 86 approx 70W YES go to 15 N B CHECK THE COIL RESISTANCE 15 Check the signal circuit emergency switch and connector side stand switch and connector YES go to 16 16 Check the cable harness continuity Check t...

Page 216: ...inuous power supply for 10 seconds and switch to ON again if the message is still displayed proceed as follows 1 Check the diagnostic tester connections YES go to 2 NO go to 3 2 Check the control unit base and continuous power supplies YES go to 4 3 Restore 4 Place the special tool between control unit and system Keep the control unit disconnected YES go to 5 Specific tooling 020481Y Control unit ...

Page 217: ...ty 10 23 insulation 1 MΩ 9 23 insulation 1 MΩ YES go to 6 NO go to 7 6 The circuit is in good working order Check the control unit 7 Fix the interruption or short circuit Injection warning light circuit CIRCUIT LAYOUT Specification Desc Quantity 1 Instrument panel 2 Fuse 7 5 A 3 electronic control unit P Specification Desc Quantity 1 TERMINAL 15 23 CONDITIONS DURING THE CHECK Nexus 500 Injection I...

Page 218: ... lasts 5 seconds The diagnostic tester is not programmed to check this circuit Proceed as follows Specific tooling 020460Y Scooter diagnosis and tester 1 Turn the switch to the ON position Turn the emergency switch to position RUN Keep the side stand raised Make sure the light goes on for 5 seconds YES go to 2 NO go to 3 2 The system is working 3 Put the special tool between the control unit and s...

Page 219: ...it is provided with an auto diagnosis function When a failure is detected the control unit turns on the injection indicator only when it is current enables the engine management check according to the data entered in the control unit where pos sible stores the failure always In the event of intermittent failures the indicator follows the failure trend and storage remains active Stored data are aut...

Page 220: ...levant circuit HV coil and relevant circuit Stepper and relevant circuit Pump relay circuit Electric fan relay circuit RAM memory ROM memory EEPROM Microprocessor Signals panel stroke revolution signal unsteady cycle Underlined failures cause the engine to stop In the other cases the engine works managed by the basic data Deleting stored failures After mounting any failures connect the diagnostic ...

Page 221: ...ector N B BEFORE WORKING ON THE FUEL SUPPLY SYSTEM CAREFULLY CLEAN THE PARTS TO PREVENT DAMAGING THE FAST RELEASE COUPLING SEAL OR TO PREVENT DIRT GETTING INTO THE DUCTS CAUTION THE SYSTEM IS UNDER PRESSURE DO NOT SMOKE DURING ANY OPERATION PREVENT ANY FUEL SPRAYING WARNING BEFORE STARTING THE ENGINE CHECK WHETHER THERE IS FUEL IN THE TANK DO NOT USE THE SCOOTER IN RESERVE FOR A LONG TIME UP TO TH...

Page 222: ... 7 HV coil 8 Fuel pump 9 Injector 10 Electronic injection control unit 11 Main remote control switch 12 Engine stop switch 13 Stand switch Removing the injector N B ONLY REMOVE THE INJECTOR FROM THE MANIFOLD IN THE EVENT OF A PROVEN DEFECT OPERATING TEST OF THE INJECTOR MUST BE PERFORMED WITH THE INJECTOR INSTALLED ON THE MANIFOLD SEE INJECTION Injection Nexus 500 INJEC 30 ...

Page 223: ...lly check to make sure the components are clean Fit new O rings and grease them Apply the recommended product to the set screws and tighten to the prescribed torque Recommended products Loctite 243 Medium strength threadlock Loctite 243 medium strength threadlock Locking torques N m injector fixing screw 3 4 N B ONCE THE ENGINE IS REPAIRED CHECK THE CO VALUE WHILE IDLING TO MAKE SURE IT IS WITHIN ...

Page 224: ... in good condition CAUTION IF AIR GETS IN IT CAN JEOPARDISE THE OP ERATION OF THE INJECTION SYSTEM ESPE CIALLY WHEN THE ENGINE IS IDLING Make sure the throttle valve and related conduit are clean Make sure the supplementary air channel man aged by the stepper motor is clean N B IF THE THROTTLE BODY IS REPLACED RESET THE T P S AND ADJUST THE CO ONCE THE ENGINE IS REPAIRED CHECK THE CO VALUE WHILE I...

Page 225: ...ouling cleaning should not be carried out when still covered by the warranty After cleaning the throttle body check and if necessary adjust C0 If these indications occur when the injection warning light turns on or further errors or wrong parameters are present it is necessary to carry out the relevant controls indicated in the manual In such a case there is a real fault evidently Refitting the bu...

Page 226: ...tem YES go to 6 Specific tooling 020460Y Scooter diagnosis and tester 6 Try to start up Select the function ERRORS in the menu Check whether there are any failures YES go to 7 YES go to 8 NO go to 28 7 Pump control relay circuit failure YES go to 9 8 Failure of injector H V coil Signals panel YES go to 18 9 The control unit has detected a failure on the line of pin 19 YES go to 10 YES go to 11 10 ...

Page 227: ...he beginning 15 Set the switch to ON with switch to RUN and side stand raised Wait more than two sec onds and check the following conditions 19 23 battery voltage YES go to 16 NO go to 17 16 Replace the control unit 17 Check the presence of voltage batt be tween pin 86 of the pump remote control switch and pin 23 of the control unit Fix the wiring if re quired Check the relay coil continuity 85 86...

Page 228: ...and replace the fuse 24 Check the ground insulation of the primary winding of the HV coil and of the injector coil YES go to 25 25 Check the pump winding resistance approx 1 5Ω YES go to 26 NO go to 27 26 Replace the fuse and check the pump 27 Check the absorbed current 28 Select the diagnostic tester menu on the AC TIVE DIAGNOSIS function Select the fuel pump simulation function Enable the functi...

Page 229: ...he light can go on whether the engine is able to run or not Circuit leak test Before performing the checks concerning the sys tem pressure it is necessary to proceed by care fully cleaning all feeding system components To perform the inspections it is necessary to use the special tooling kit for fuel pressure check Specific tooling 020480Y Petrol pressure check set Before disconnecting any fastene...

Page 230: ...ecessary to press the coaxial rings towards the pump and extract the terminals CAUTION DO NOT FORCE THE TERMINAL IF THIS DOES NOT COME LOOSE EVENTUALLY TRY TWISTING IT THE TERMINAL IS DESIGNED SO THAT AN INCREASE IN TENSION INCREA SES THE LOCKING FORCE The system pressure check must be carried out for practical reasons by connecting on the pump side Connect the manometer to the outlet duct RHS and...

Page 231: ...the return duct is not clogged or squashed YES go to 6 NO go to 7 6 Replace the pressure regulator 7 Pressure regulation too low Start the pump rotation again Using pliers with flat and long tips temporarily clamp the return duct by the extension of the specific tool the serial pipe does not allow this operation fuel pressure over 300 KPa 3 BAR YES go to 8 NO go to 9 8 Replace the pressure regulat...

Page 232: ...l pressure check set 3 Check the system seal Start the pump for 30 seconds using the diagnostic tester When the pump stops wait 3 minutes Check the system pressure Fuel pressure over 200 KPa 2 BAR YES go to 5 NO go to 6 Specific tooling 020460Y Scooter diagnosis and tester 4 If pressure is lower carefully check the voltage with pump under stress If voltage is higher than 12 V replace the pump 5 Th...

Page 233: ...e slowly YES go to 12 NO go to 13 Specific tooling 020480Y Petrol pressure check set 12 Check and replace the injector if required due to an insufficient seal see THERMAL UNIT AND TIMING SYSTEM 13 There are no trend variations Repeat the test clamping the pipe of the special tool in the portion between the branch and the pump Check whether pressure decreases much more slowly YES go to 14 NO go to ...

Page 234: ...cific tooling 020460Y Scooter diagnosis and tester 18 The fuel filter is not clogged The scooter can be used respecting the limit of 48000 km 19 The flow rate is less than 250 cc The fuel filter is dirty Replace the pump support Pump electrics check This section describes the operations to be carried out to perform electric checks on the pump Resistor check Disconnect the connector from the pump s...

Page 235: ... tester probes in ammeter function see figure Check the pump rotation and power consumption N B THIS CONSUMPTION REFERS TO POWER SUPPLY VOLTAGE approx 12 V PUMP RUN IN SYSTEM PRESSURE 300 KPA 3 BAR FUEL FILTER CLEAN Electric characteristic Current consumption approx 3 5 4 2 A The a dirty filter causes an increase of the absorption If the overpressure valve opens the pump ab sorbs approx 6 7A In ca...

Page 236: ...t the engine and wait for the spontaneous stop Clean the tank and the pump support wash and blow with compressed air if necessary Disconnect the delivery and return pipes by the quick unions CAUTION PREVENT ANY FUEL SPRAYING Loosen the pump support mounting ring nut RH threading Remove the pump support and the sealing gas ket N B WHEN EXTRACTING BE CAREFUL NOT TO DEFORM THE FLOATING ARM Injection ...

Page 237: ...act the level indicator from the support Level indicator check The check may also be carried out before removal from the support Measure the resistance between the two level indicator wires Moving the float arm check that the resistance is subject to gradual variations according to the arm motion LIMIT VALUES Specification Desc Quantity 1 Empty tank position 95 105 Ω 2 Full tank position 0 9 Ω Rep...

Page 238: ...N SIDE Lubricate the O rings and repeat the operations in the reverse order for re assembly 3 Fuel pump Note the position of the power supply wires on the support pos 1 positive red pos 4 negative black Disconnect the power supply cables Cut the delivery pipe mounting band on the sup port Injection Nexus 500 INJEC 46 ...

Page 239: ...pump requires replacement remove the pre filter and the annular support For re assembly perform the removal operations in the reverse order using a new band for the de livery pipe and a new pump mounting washer N B TO CLEAN THE PRE FILTER USE PETROL AND COMPRESSED AIR Orientate the pump properly Nexus 500 Injection INJEC 47 ...

Page 240: ...rm Place the sealing gasket on the tank Install the pump support onto the seat aligning the connector with the scooter longitudinal axle N B AN INCORRECT ORIENTATION MAY IMPAIR THE LEVEL INDICATOR PERFORMANCE Screw the mounting ring nut and tighten thoroughly Locking torques N m Electric pump locking ring nut 20 Connect the feeding circuit pipes again and check the proper introduction by pulling a...

Page 241: ...IRCUIT LAYOUT Specification Desc Quantity 1 Electronic control unit 2 Injector 3 HV coil 4 Pump 5 Control unit remote control switch 6 Fuse 10 A 1 Connect the diagnostic tester Select the menu on the ACTIVE DIAGNOSIS function Select the INJECTOR function YES go to 2 Specific tooling 020460Y Scooter diagnosis and tester Nexus 500 Injection INJEC 49 ...

Page 242: ... The injection tester displays test failed YES go to 9 NO go to 6 6 No injector openings detected The injection tester displays test successful YES go to 8 7 The injector control circuit is efficient Perform the injector hydraulic check 8 The injector control circuit is efficient Repeat the acoustic check and perform the injector hy draulic check for safety reasons 9 Select the menu on the ERRORS ...

Page 243: ... 2 seconds YES go to 16 NO go to 17 16 The injector electric circuit is steady Repeat the checks If the fault continues check the control unit connector If necessary replace the electronic control unit 17 Repeat the test using the resistance multime ter Check the resistance between pin 13 and pin 87 black green cable of the pump remote control switch 13 black green 14 5Ω 5 resistance of the inject...

Page 244: ...tment Install the fuel pressure check kit special tool In this case the injector can be connected directly to the tool quick couplings AHEAD go to 2 Specific tooling 020460Y Scooter diagnosis and tester 020480Y Petrol pressure check set 2 Prepare a graduated container with minimum capacity of 100 cm3 and a resolution of 10 20 cm3 Connect the injector to the wire supplied with the injection tester ...

Page 245: ...ntinues replace the injector THERMAL UNIT AND TIMING SYS TEM The injector atomisation cannot be checked by simple methods The injector is provided with 5 holes whose angulation forms a jet with a taper of about 80 The jet thus formed impinges both in take valves N B AN INJECTOR WITH LOW FLOW RATE AF FECTS THE MAXIMUM PERFORMANCE AN INJECTOR WITH POOR SEAL AFFECTS IDLING AND THE START UP FEATURES A...

Page 246: ...reful of the following 1 check that terminals are not bent check that connectors are properly engaged Check whether the failure changes if the connector is slightly vibrating 3 Before replacing the EMS control unit check the whole system carefully If the fault is fixed by replacing the EMS control unit install the original control unit again and check whether the fault occurs again 4 For troublesh...

Page 247: ...ED P Specification Desc Quantity 1 Main fuse 30 A 2 Fuse 7 5 A 3 Fuse 3 A 4 Fuse 5A 5 Stand switch 6 Emergency switch 7 Key switch 8 Engine stop remote control switch 9 Main remote control switch 10 Diode 2 A 11 Instrument panel 12 Immobilizer LED 13 Decoder 14 Immobilizer aerial 15 Electronic control unit ECU Nexus 500 Injection INJEC 55 ...

Page 248: ...figure The LED is turned on by the decoder The control unit data can be checked by the diag nostic tester Specific tooling 020460Y Scooter diagnosis and tester To connect the diagnostic tester open the spark plug inspection port and pull out the EMS Diagno sis socket Remove the protection cap and con nect the tester terminal Power the diagnostic tester by connecting the ter minals to the battery p...

Page 249: ...ies of the key repeat the operation with each key Insert the master key again and set to ON for 2 seconds The maximum time to change keys is 10 seconds Seven service keys black coloured can be programmed within the same storage operation It is essential to adhere to the times and the procedure If you do not start again from the beginning Once the system has been programmed master key transponder d...

Page 250: ...er of keys used for programming WITH SERVICE KEYS Deterring blink Switching from ON to OFF with programmed system causes the intermittent switching on of the LED with an antitheft effect This occurs with any key used for programming If the scooter is not used the deterrent light stops automatically after 48 hours to prevent discharging the battery A new 48 h cycle starts by switching from OFF to O...

Page 251: ... system again Programming is indispensable for the engine start up see System programming 3 Control unit replacement Programming is indispensable when the control unit is replaced to enable the engine start up In this case it is sufficient to switch to ON using the master key N B THE SERVICE KEY BLACK COLOURED IS NOT USED FOR PROGRAMMING WHEN NOT PROGRAMMED THE CONTROL UNIT ALLOWS NO FUNCTIONAL DI...

Page 252: ...nect the special tool between the injection system and the control unit Remove the main decoder connector N B TO ACCESS THE COMPONENTS SEE THE COMPONENTS LAYOUT CHAPTER Specific tooling 020481Y Control unit interface wiring 1 Using a multimeter check the continuity be tween pin 16 of the control unit and pin 6 of the decoder connector YES go to 3 NO go to 2 2 Repair or replace the wiring 3 Check t...

Page 253: ... the mas ter key Replace the transponder using one from the new cylinder kit Replace decoder and control unit Program again 3 Check the proper connection of the aerial con nector YES go to 5 NO go to 4 4 Restore the connection and check the presence of the code 5 Disconnect the aerial connector and check con tinuity 8 2 W YES go to 7 NO go to 6 6 Replace the aerial 7 Check the proper position of t...

Page 254: ...to 4 4 Restore 5 Replace decoders and control unit Program the components again Code 4 Code no 4 denotes a system where the decoder is blank and the control unit is programmed The key is recognised by the control unit Start up disabled Indicator light N B REPEAT THE KEY PROGRAMMING PROCEDURE USING THE ORIGINAL MASTER KEY Diagnosis guide Immobiliser LED does not come on 1 Check whether the injectio...

Page 255: ...uring between the decoder connector and the 8 pin connector of the instrument panel YES go to 8 NO go to 10 8 Check for positive battery voltage on the red black cable of the 8 way connector of the instru ment panel YES go to 9 NO go to 10 9 Faulty led replace the instrument panel 10 Repair or replace the wiring 11 If the injection light does not come on continue with the check of the supply circu...

Page 256: ...of the crankshaft The sensor is of the reluctance variation type and is therefore comparable to an alternate current al ternator that powers the control unit The signal frequency is interrupted by the vacuum generated by the two missing teeth on the wheel speed sensor The sensor signal is fundamental for obtaining starting of the engine The CPU autodiagnosis is enabled on this circuit in 2 differe...

Page 257: ...The light remains on during the period the cycle is reconstructed If the revolution timing signal is completely missing due to mechanical faults or lack of magnetic activity it will be impossible to start the engine or it will stop while driving and the autodiagnosis will not be able to record any faults To check the sensor and related circuit proceed as follows 1 Connect the scooter tester Select...

Page 258: ...e rpm engine indication YES go to 6 NO go to 7 6 The signal panel is in conformance 7 CHECK THE AIR GAP AND MAGNETIC AC TIVITY OF THE SENSOR See engine mechanics 8 Check the sensor and related connection circuit with the control unit AHEAD go to 9 9 Install the connection wiring between the control unit and injection system Do not make the con nection with the control unit CONTINUE at 10 Specific ...

Page 259: ...ectric characteristic S infinite MΩ YES go to 13 NO go to 12 12 Replace the revolution sensor 13 Reconnect the revolution timing sensor con nector Repeat the resistance check through the injection wiring pin 7 pin 12 Electric characteristic 7 12 680 Ω 100 Ω Model with 2 clamps 7 12 890 Ω 130 Ω Model with 1 clamp The value should be very close to that detected directly by the sensor YES go to 17 NO...

Page 260: ... the injection wiring 19 Measure the alternated voltage between pins 7 and 12 with engine at start up speed Electric characteristic 7 12 approx 0 8 4 5 V eff Revolution speed approx 300 400 rpm YES go to 20 NO go to 21 20 The sensor circuit is in conformance Use the parameter function to check if the engine rpm indication is present when trying to start If not carefully check the CPU connection co...

Page 261: ... 1 Electronic control unit 2 Injector 3 HV coil 4 Pump 5 Control unit remote control switch 6 Fuse 10 A The ignition system is integrated with the injection and is of the inductive high efficiency type The control unit manages two important parame ters Ignition advance This is optimised according to the engine rpm to the engine load temperature and ambient pres sure With idle engine it is optimise...

Page 262: ...er 2 The tester displays TEST FAILED Repeat the test and wait for the tester to display TEST SUC CESSFUL YES go to 3 NO go to 4 3 Select the menu on the ERRORS function Check the presence of current or stored errors relating to the H V coil YES go to 6 NO go to 5 4 Test failed YES go to 6 5 The coil control circuit is efficient Check the H V coil secondary the cable and the screened cap 6 Install ...

Page 263: ... the voltage check between the black green wire and earth Electric characteristic Black green 23 battery voltage coupled to the pump rotation 2 seconds YES go to 10 NO go to 9 9 Check the black green wire continuity Repair or replace the wiring N B A FAILURE OF THE REMOTE CONTROL SWITCH WOULD CAUSE THE PUMP ROTATION FAIL URE 10 The positive power supply is conforming Check the continuity between t...

Page 264: ...c characteristic 20 23 Ω infinite 1MΩ YES go to 15 NO go to 14 13 Repair or replace the faulty system Repeat the check with the menu on ACTIVE DIAGNOSIS 14 Repeat the earth insulation check in the two sections Repair or replace the wiring Repeat the check with the menu on ACTIVE DIAGNOSIS H V coil control simulation Delete the errors stored in memory 15 Check the continuity of the H V coil primary...

Page 265: ...between one of the primary terminals and earth Electric characteristic Primary earth Ω infinite 1MΩ YES go to 17 NO go to 1 9 17 Check the secondary resistance Measure the resistance between one of the primary terminals and the spark plug cable output Electric characteristic Primary HV cable output 3 1 K 9 Nexus 500 Injection INJEC 73 ...

Page 266: ...HAPTERS Spark advance The ignition advance is determined electronically on the basis of parameters known by the control unit For this reason it is not possible to declare the reference values based on the engine rpm The ignition timing value is detectable any time using the diagnostic tester It is possible to check whether the ignition advance determined by the system does in fact correspond with ...

Page 267: ...ter Remove the TDC reference inspection cap be tween flywheel and crankcase cover See the fly wheel cover chapter By the driving pulley turn the engine to find the alignment of the references to identify the TDC Repeat for the reference between driving pulley and engine crankcase Nexus 500 Injection INJEC 75 ...

Page 268: ...ne position 1 spark 2 revs Check that the real values of rpm and ignition advance match those measured using the diag nostic tester If the values do not match check distribution timing revolution timing sensor Injection control unit Coolant temperature sensor Electric characteristic TERMINALS 4 22 CONDITIONS coolant temperature STANDARD With connected sensor 20 2500 100 Ω 80 308 6 Ω Injection Nexu...

Page 269: ...oper management of the ignition Such failure is more easily detected upon the engine start up To check the sensor and related circuit proceed as follows 1 Connect the injection diagnostic tester and select the menu on the errors function Check whether faults have been recorded regarding the coolant temperature sensor YES go to 3 NO go to 2 Specific tooling 020460Y Scooter diagnosis and tester 2 Th...

Page 270: ...es the values de clared according to the temperature Electric characteristic TEMPERATURE RESISTANCE 9 6KW 10 C 5 975KW 0 3 81KW 10 C 2 5KW 20 C 1 68KW 30 C 0 3KW 80 C YES go to 10 NO go to 9 9 Replace the sensor 10 Connect the sensor connector and repeat the resistive check at terminals 4 and 22 Electric characteristic 4 22 Resistance equal to the value directly detected at the sensor YES go to 13...

Page 271: ...cuit is earth insulated Electric characteristic 4 23 ohm infinite 1Mohm 22 23 ohm infinite 1Mohm YES go to 15 NO go to 14 14 Repair or replace the wiring Check the air temperature lines and the throttle valve position YES go to 13 15 Connect the special tool to the control unit Set the switch to ON with switch to RUN and side stand raised YES go to 16 Nexus 500 Injection INJEC 79 ...

Page 272: ...O go to 17 17 Electric characteristic Measured value 5 0 2 V Repeat the wiring and sensor continuity checks YES go to 18 18 Electric characteristic Measured value 0 V Repeat the sensor and circuit earth insulation check YES go to 19 NO go to 20 19 Check the control unit connector Check the control unit power supply Replace the control unit if necessary 20 Repair or replace the cable harness Inject...

Page 273: ...ECK OF THE SENSOR REMOVE IT FROM THE ENGINE AND CHECK ITS RESISTANCE AT CONTROLLED TEMPERATURE USING A SUITABLE CONTAINER IMMERSE THE METAL PORTION OF THE SENSOR IN WATER HEAT GRADUALLY AND READ THE TEMPERATURE AND RESISTANCE VALUES CHECK THE MATCHING AS PER TABLE Intake air temperature sensor Electric characteristic TERMINALS 18 22 CONDITIONS Sucked air temperature 20 STANDARD With connected sens...

Page 274: ...ensor and related circuit proceed as follows 1 Connect the diagnostic tester Select the function ERRORS in the menu Check whether there are any indications regarding the sucked air temperature sensor YES go to 3 NO go to 2 Specific tooling 020460Y Scooter diagnosis and tester 2 The EMS system has received no indications of temperatures out of the range of possible values If you suspect a wrong tem...

Page 275: ...nnect the sucked air temperature sensor connector Measure the resistance between the sensor terminals Check that the resistance matches the values declared according to the temperature TEMPERATURE RESISTANCE Specification Desc Quantity 1 9 6 Kohm 10 C 2 5 975 Kohm 0 3 3 81 Kohm 10 C 4 2 5 Kohm 20 C 5 1 68 Kohm 30 C YES go to 10 NO go to 9 9 Replace the sensor 10 Connect the sensor connector and re...

Page 276: ...tween the two lines with disconnected connectors Electric characteristic Grey white 18 0 ohm continuity Light blue green 22 0 ohm continuity YES point 12 12 Repair or replace the cable harness YES go to 10 13 Check that the sensor circuit is earth insulated Electric characteristic 18 23 infinite 1 Mohm 22 23 infinite 1 Mohm Injection Nexus 500 INJEC 84 ...

Page 277: ... in RUN and side stand raised YES go to 16 Specific tooling 020481Y Control unit interface wiring 16 Measure voltage at terminals 18 and 22 Electric characteristic 18 22 V as in the table TEMPERATURE VOLTAGE Specification Desc Quantity 1 X V 10 C 2 X V 0 3 X V 10 C 4 X V 20 C 5 X V 30 C 6 X V 80 C YES go to 21 NO go to 17 17 Electric characteristic Measured value 5 0 2 V Nexus 500 Injection INJEC ...

Page 278: ... IDLE ENGINE Pressure sensor This sensor does not have a system since it is di rectly installed into the control unit The sensor allows the control unit to optimise the engine performance based on altimetric varia tions To check the sensor proceed as follows 1 Connect the diagnostic tester Select the function ERRORS in the menu Check whether there are any indications regarding the pressure sensor ...

Page 279: ...ection control unit Throttle valve opening sensor Throttle position sensor t p s Electric characteristic TERMINALS 1 22 CONDITIONS Switch set to ON STANDARD 5 V TERMINALS 11 22 CONDITIONS Opening the throttle gradually STANDARD Volt Progressive increase Nexus 500 Injection INJEC 87 ...

Page 280: ... the injection indicator and the tripping of the safe ties In these conditions the engine works even though not in an optimum way always safeguard ing the catalytic converter integrity The throttle valve position signal is especially im portant at the small valve openings These areas are also where the sensor works more frequently and therefore they require more frequent checks after a high number...

Page 281: ...the opening variation YES go to 5 NO go to 6 5 The throttle valve position signal is conforming 6 Connect the special tool to the injection system Do not connect the tool to the control unit Disconnect the throttle valve position sensor connector Check the continuity between the connector s terminals and the relevant pins on the control unit Specific tooling 020481Y Control unit interface wiring E...

Page 282: ... to 8 10 Connect the special tool to the control unit Set the switch to ON with switch to RUN and side stand raised Measure voltage between terminals 1 and 22 of the special tool Specific tooling 020481Y Control unit interface wiring Electric characteristic 1 22 5 0 2 V YES go to 12 NO go to 11 11 Check the control unit connector Replace the control unit if necessary YES go to 10 Injection Nexus 5...

Page 283: ... 22 V progressive variation The possible variations of the limit values are caused by the sensor installation tolerances YES go to 15 NO go to 14 14 Replace the throttle body along with sensors and stepper YES point 12 15 Check that the voltage measured at pins 11 and 22 matches that indicated by the diagnostic tester set to PARAMETERS YES go to 16 NO go to 17 16 The throttle valve position sensor...

Page 284: ... For these reasons the mVs of the sensor with the valve at minimum can vary from one throttle body to another To obtain the optimum fuel preparation especially at small openings of the throttle valve it is essential to match the throttle body with the control unit following the procedure known as TPS resetting With this operation we inform the control unit as the starting point of the mV value cor...

Page 285: ...ould be performed in the following cases on first fitting in case of replacement of the throttle body if the injection control unit is replaced N B THE TPS RESETTING PROCEDURE MUST NOT BE CARRIED OUT WITH A USED THROTTLE BODY BECAUSE POSSIBLE VALVE WEAR AND STOP WEAR FOR THE MINIMUM OPENING MAKE THE AIR FLOW DIFFERENTLY FROM THAT OF PRE CALIBRATION Nexus 500 Injection INJEC 93 ...

Page 286: ...it only when the opening must be changed The revolution is divided into portions called steps By changing the opening steps it is possible to properly feed the engine to facilitate the start up procedure and adjust the air feeding with cold en gine When the engine reaches the working tem perature the stepper partly closes again To prevent wear of the adjustment piston opera tion at full speed is o...

Page 287: ...electric checks inspect the throttle valve and the auxiliary air circuit cleaning To check the stepper and the relevant circuit pro ceed as follows 1 Connect the diagnostic tester Set the switch to ON with switch to RUN and side stand raised Lift the scooter on the central stand Select the function ERRORS in the menu Check whether the control unit has detected any failures relating to the stepper ...

Page 288: ...whether the stepper controls some rev olution variations and wait for the diagnostic tester response N B THE CPU ENABLES THE DIAGNOSIS ONLY WHEN THE IDLE SPEED IS WITHIN THE SPECIFI CATIONS YES go to 6 NO go to 8 6 Test successful Variations of revolutions perceived YES go to 7 NO go to 9 7 Stepper and relevant circuit efficient 8 Test failed No change in the rpm check the stepper circuit Disconne...

Page 289: ...ve replace the throttle body 10 Replace the throttle body 11 Connect the special tool For these checks do not connect the special tool to the control unit Check the continuity of the 4 power supply lines of the stepper Specific tooling 020481Y Control unit interface wiring Electric characteristic A Light blue red 14 0 Ω continuity B Orange blue 6 0 Ω continuity C Light blue yellow 21 0 Ω continuit...

Page 290: ...1 MΩ infinite 6 23 1 MΩ infinite 21 23 1 MΩ infinite 24 23 1 MΩ infinite YES go to 14 NO go to 13 13 Repair or replace the wiring YES go to 11 14 Connect the stepper connector Repeat the continuity check with the tool pins Electric characteristic 14 24 approx 51 Ω 6 21 approx 51 Ω Injection Nexus 500 INJEC 98 ...

Page 291: ... on the stepper command lines Set up for direct voltage measurements N B PULSES ARE USED TO CHANGE THE STEPPER POSITION Electric characteristic 14 24 V pulses for a few seconds 6 21 V pulses for a few seconds After reaching the optimum position the power supply voltage becomes null YES go to 17 NO go to 18 17 The stepper circuit is efficient 18 Check the control unit connector Replace the control ...

Page 292: ...Injection Nexus 500 INJEC 100 ...

Page 293: ...INDEX OF TOPICS SUSPENSIONS SUSP ...

Page 294: ...he sen sor that detects movement in the odometer Front wheel hub overhaul Check that the wheel bearings are free from wear If you have to replace the wheel bearings proceed as follows Remove the 2 bearings on the odometer motion drive side using pliers 14 or 34 and bell 9 Remove the inside spacer Specific tooling 001467Y014 Pliers to extract ø 15 mm bearings 001467Y034 Extraction pliers for ø 15 m...

Page 295: ... tooling 020376Y Adaptor handle 020456Y Ø 24 mm adaptor 020412Y 15 mm guide Heat the LH bearing seat using the thermal gun Insert the bearing by the punch consisting of adapter handle adapter 42x47 mm and 15 mm guide to abutment Reinsert the spacer bushing on the brake disc side by the specific tool and move it to abutment Specific tooling 020376Y Adaptor handle 020359Y 42x47 mm adaptor 020412Y 15...

Page 296: ...to abutment Specific tooling 020376Y Adaptor handle 020357Y 32 x 35 mm adaptor 020412Y 15 mm guide Check that the wheel axle is free from wear or deformations Replace them if necessary Refitting the front wheel To refit carry out the removal operations but in reverse order observing the prescribed torques Place the odometer movement sensor until the reference correctly fits into its slot Locking t...

Page 297: ...n the shield back plate Using the special tool loosen and remove the up per ring nut the spacer washer and the counter ring nut Extract the fork N B TAKE CARE TO SUPPORT THE FORK SO AS TO PREVENT IT FROM COMING OFF ABRUPT LY Specific tooling 020055Y Wrench for steering tube ring nut Overhaul Check the spring length Check the length A of the spring Characteristic Standard spring length 291 6 mm Nex...

Page 298: ...BE REMOVED ONLY IF STRICTLY NECESSARY In case of replacement proceed as follows Using a bearing removal punch inserted from the bottom remove the top seat on the steering head Then remove the bottom seat of the tapered bear ing inserting the punch from the top of the head stock Specific tooling 020004Y Punch for removing fifth wheels from headstock Servicing fork stems Using an inside 17 mm hexago...

Page 299: ...ing member rota tion insert an inside 22 mm hexagon spanner into the stem Remove the pumping member Remove the dust guard ring using a screwdriver as shown in the figure N B BE CAREFUL NOT TO DAMAGE THE DUST GUARD AND THE STEM Remove the oil guard safety lock using a screw driver Repeatedly actuate the stem to remove it from the fork leg Nexus 500 Suspensions SUSP 7 ...

Page 300: ...Install the bushing from the bottom of the stem Insert the following from the top of the stem 1 Bushing B 2 Abutment washer C 3 Oil guard D Insert the pumping member guiding bushing at the bottom end of the stem Insert the stem into the casing being careful not to let the guiding bushing come out of the stem Move the oil guard in abutment using a tube Suspensions Nexus 500 SUSP 8 ...

Page 301: ... come out of the stem Insert and screw the pumping member screw with a new copper washer and tighten to the prescribed torque CAUTION TO PREVENT THE PUMPING MEMBER ROTA TION INSERT AN INSIDE 22 MM HEXAGON WRENCH INTO THE STEM Locking torques N m Pumping element fixing screw 25 35 Pour recommended oil into the stem Recommended products AGIP FORK 7 5W Oil for front fork Hydraulic oil SAE 7 5W Charac...

Page 302: ... using the specified product Recommended products AGIP GREASE PV2 Grease for the steering bearings pin seats and swinging arm White anhydrous calcium based grease to protect roller bearings temperature range between 20 C and 120 C NLGI 2 ISO L XBCIB2 Insert the fork into the headstock Insert the tapered bearing after applying the specified product Recommended products AGIP GREASE PV2 Grease for th...

Page 303: ... front and rear handlebar covers as described in the section Scooter body Install the front mudguard Install the front wheel Install the front brake callipers Tighten the retaining screws of the brake calliper to the support Specific tooling 020055Y Wrench for steering tube ring nut Locking torques N m Screw securing handlebar to steering tube 45 50 Holding torque of lower ring nut 20 25 Upper ste...

Page 304: ...ate in the upper end of the steering tube Insert the special tool as shown in the figure Insert the retaining band of the two half rings Using a 19 mm hexagonal spanner extract the roller bearing Specific tooling 020458Y Puller for lower bearing on steering tube Suspensions Nexus 500 SUSP 12 ...

Page 305: ... in the figure Using two 24 mm wrenches tighten the screw to move the two seats in abutment N B ALWAYS USE A NEW BEARING AND A NEW SEAT Specific tooling 001330Y Tool for fitting steering seats Reassembly of tapered bearing in steering tube Insert the a new plate and a new dust guard in the steering tube Insert the a new tapered bearing in the steering tube Using the special tool and a mallet to mo...

Page 306: ...ength threadlock The scooter has a Power Drive progressive rear suspension system combined with the Direct Link system of engine mounting on the frame that gives exceptional rigidity to the whole system The scooter has a special connecting strut between engine and frame that allows the travel gear to be adjusted to 15 positions If is thus possible by turning the ring nut on the lower part of the s...

Page 307: ... Remove the muffler support arm Remove the spacer on the gear shaft Loosen the five gear shaft fastening nuts using the rear brake Refitting the rear wheel For reassembly perform the previous operations in the reverse order Locking torques N m Wheel fastening screws 33 37 Nexus 500 Suspensions SUSP 15 ...

Page 308: ...s fixing pin Move the engine backwards so that spacers can be removed Remove the left spacer shown in the figure Remove the central and the right spacers To refit perform the operation in reverse order carefully respecting the locking torque and lubri cate the area marked A for the right spacer on the engine bearing to slide Locking torques N m Engine chassis fixing pin 100 120 Two different types...

Page 309: ...ngs from the centre stand Loosen the fastening nuts Remove the centre stand On refitting tighten the nut to the specified torque Locking torques N m Central stand retainers 25 30 Centre stand We wish to inform you that from Chassis No ZAPM3510000007012 a new centre stand has been introduced to improve the function The new stand differs from the old stand in having a 5 mm longer stand arms increasi...

Page 310: ...Side stand Unhook the springs Loosen the nut Pull out the screw Fitting Carry out the previous operations in reverse order Locking torques N m Side stand clamp 15 20 Suspensions Nexus 500 SUSP 18 ...

Page 311: ...INDEX OF TOPICS BRAKING SYSTEM BRAK SYS ...

Page 312: ...the pump pressure exceeds 8 bar front and rear brake operate simultaneously In this phase the increases in the pump pressure are detected by both the callipers When the front brake pressure reaches 23 bar a new phase of limitation starts Any increments in the pump pressure will be detected in linear mode by the rear calliper The front calliper only detects slight increases for example 80 bar rear ...

Page 313: ...pad retaining pin until the circlip is released Remove the screws fixing the brake calliper to the bracket then remove the brake calliper com plete with pipe Complete the extraction of the pad retention pin the spring and the pads N B IF BRAKE CALLIPER REPLACEMENT OR SERVICE IS NEEDED BEFORE REMOVING THE CAL LIPER CLAMPS TO THE SUPPORT BRACKET LOOSEN THE OIL JOINT FITTING Nexus 500 Braking system ...

Page 314: ...f calliper N B WHEN REMOVING THE O RINGS BE CARE FUL NOT TO SCRATCH THE HALF CALLIPER SEATS Check that the pistons and their seats show no scratches Wash and blow all the components carefully Fit new sealing rings and dust guards Refit the plungers in their seats being careful to lubricate with brake fluid Couple the half calliper and tighten the two screws to the prescribed torque N B TO AVOID DA...

Page 315: ...he bleed screw as shown in the photograph Insert the circlips on the pad fixing pin N B FAILURE TO RESPECT THE PAD POSITIONING REQUIREMENTS WITH RESPECT TO THE DI RECTION OF ROTATION COULD INHIBIT PROPER BRAKE FUNCTION AND QUIETNESS Keep the brake pads in contact with the plungers and insert the calliper in the brake disc Fix the calliper to the support with the two screws with spring washer to th...

Page 316: ... Check the good condition of the brake hoses of the seals and of the respective fittings If any loss of brake fluid is discovered at the brake callipers the callipers must be replaced Remove the two retaining screws of the front brake calliper at the fork as indicated in the photo N B BEFORE STARTING TO SERVICE OR RE PLACE THE CALLIPER LOOSEN THE CON NECTION OF THE PRESSURE HOSE AT THE BRAKE CALLI...

Page 317: ...l and blow all the compo nents carefully Fit new sealing rings and dust guards Assembly the pistons into the appropriate seats being careful to lubricate the sealing ring B with brake fluid The dust guard ring A has an inter nal groove with specific grease Decouple the floating support of the calliper body separating the 2 rubber dust covers off their seats N B TO EXTRACT THE LONG DUST COVER PULL ...

Page 318: ...nt brake calliper 20 25 Rear brake disc Removal Remove the rear brake calliper Remove the brake disc with hub from the wheel axle To remove the brake disc from the hub support the unit in a vice and tighten the 5 fastening bolts with self locking nuts Refitting To reassemble the brake disc on the hub carry out the removal operations in the reverse order ar ranging the brake disc on the hub on the ...

Page 319: ...n in the figure Characteristic Standard thickness 5 02 01mm Minimum thickness allowed after use 3 5 mm Repeat the measurement in at least 6 points of the disc Check that the measurements do not give devi ations higher than Check that the brake disc unit rotates regularly using the specific tool fixed on the brake caliper support as shown in the figure Suitably fix the flange to the wheel axle with...

Page 320: ...hown in the photograph Refitting Perform the removal operations in the reverse order according to the direction of rotation of the disc as shown by the arrow on the disc Tighten the 5 screws at the prescribed torque Locking torques N m Front brake disc mounting 5 6 Disc Inspection Using a micrometer check the disc thickness as shown in the figure Characteristic Standard thickness 4 02 01mm Braking...

Page 321: ...front wheel make it rotate and check the disc deviation Specific tooling 020335Y Magnetic support for dial gauge Characteristic Max deviation xxx mm Front brake pads Removal Remove the front brake calliper unscrewing the 2 retainers but leaving the hoses connected Disengage the upper part of the pad from the seat located into the calliper body Using a calliper remove the 2 retaining pins of the pa...

Page 322: ...tip into the groove and pressing it towards the thrust spring to facilitate inserting the pin Insert the pad fixing pin from the reaction plate side so that the pin head clicks in the seat in the groove on that plate Insert the 2 locking split pins of the pin orientating the heads towards the calliper body as shown in the figure Braking system Nexus 500 BRAK SYS 12 ...

Page 323: ...pads according to the direction of rotation of the brake disc as indicated by the arrow on the anti vibration pad Insert the pad mounting pin and the retaining spring with its ends facing the bleed screw as shown in the figure Insert the retaining ring on the pin Fasten the rear brake calliper to the bracket and tighten the 2 screws to the prescribed torque Locking torques N m Pipe joint brake cal...

Page 324: ...nt left calliper To access the regulating valve it is necessary to remove the front shield Top up the brake fluid to the right level in the tank N B DURING THE BLEEDING OPERATIONS MAKE SURE THE BRAKE FLUID DOES NOT COME INTO CONTACT WITH THE BODYWORK SO AS NOT TO DAMAGE IT FURTHERMORE DURING THE BLEEDING OPERATIONS REGARDING THE BRAKE CALLIPERS MAKE SURE THE BRAKE FLUID DOES NOT COME INTO CONTACT ...

Page 325: ...er the bleed screw Top up the brake fluid to the right level in the tank N B DURING THE BLEEDING OPERATIONS MAKE SURE THE BRAKE FLUID DOES NOT COME INTO CONTACT WITH THE BODYWORK SO AS NOT TO DAMAGE IT FURTHERMORE DURING THE BLEEDING OPERATIONS REGARDING THE BRAKE CALLIPERS MAKE SURE THE BRAKE FLUID DOES NOT COME INTO CONTACT WITH THE DISC BRAKES AND WITH THE BRAKE PADS FAILURE TO COMPLY WITH THIS...

Page 326: ...the pump undoing the screw indicated in the figure Remove the stop light switch connector BRAKE PUMP TECHNICAL DATA Specification Desc Quantity Pump right piston diameter Ø 12 Left piston pump diameter Ø 15 Refitting To refit carry out the removal operations but in reverse order respecting the prescribed locking torques Locking torques N m Pipe joint brake calliper 20 25 Rear brake pump combined B...

Page 327: ... the combined system Remove the front knee guard Loosen fitting 1 shown in the figure for the rear brake calliper N B INSERT A CLOTH UNDER THE DISTRIBUTION VALVE TO AVOID BRAKE FLUID DRIPPING ONTO THE PLASTIC OR OTHER COMPO NENTS OF THE SCOOTER Remove fitting 2 of the front brake calliper Remove fluid inlet fitting 3 from the pump to the valve Remove the 2 TCEI socket head retaining screws of the ...

Page 328: ...stem as described in the relevant section Locking torques N m Coupling for oil on the integral braking system pump 16 20 Coupling on the integral braking system device from the pump 20 25 Front brake calliper integral braking system device coupling 20 25 Rear brake calliper integral braking system device coupling 20 25 Braking system Nexus 500 BRAK SYS 18 ...

Page 329: ...INDEX OF TOPICS COOLING SYSTEM COOL SYS ...

Page 330: ...radiator cold box is connected to the lower side of the expansion tank in the fluid When the engine is cold the thermostat output to the radiator is closed even though there is still a little flow for de aeration obtained by a hole into the closing plate In this case the circulation into the thermal unit is active to ensure an even heating Once the working temperature has been reached the main cir...

Page 331: ...deviator Starts opening 82 2 C ELECTRIC VENTILATION Specification Desc Quantity Type With piston Electric ventilation start 107 C Electric ventilation end 103 C WATER PUMP Specification Desc Quantity Type Centrifugal Control Coaxial at the countershaft RADIATOR Specification Desc Quantity Type Aluminium with horizontal circulation EXPANSION TANK Specification Desc Quantity Calibration Automatic bl...

Page 332: ... 107 C CAN ONLY BE MANAGED BY A SYSTEM SUP PLIED WITH A 50 MIXTURE AND PRESSURISED AT 0 9 BAR AVOID STARTING THE ENGINE WITHOUT PRESSURISATION SINCE IT MAY REACH THE BOIL ING TEMPERATURE BEFORE THE ELECTRIC FAN STARTS WORKING IN CASE OF AN INCREASE OF THE ELECTRIC FAN START TIME CHECK THE THERMOSTAT OPENING TEMPERATURE AND CHECK THAT THE COOLANT DENSITY IS CORRECT THE OP TIMUM DENSITY IS OBTAINED ...

Page 333: ...t the venting union with the expansion tank filler Loosen the vent and start the engine Keep it open until the air has been fully vented Close the bleed screw Stop the engine Restore the level into the expansion tank and tighten the cap Start the engine and let it warm up to reach the electric ventilation temperature Stop the engine Restore the level with cold engine CAUTION ELECTRIC VENTILATION I...

Page 334: ... the crankcase in the oil seal area and on the motion sensor Check that the ceramic seal surfaces are not scratched or worn Check that there are no damages or dents on the outside diameter of the bypass Characteristic Outside diameter 10 5 mm Check the free length of the spring Characteristic Standard length 65 2 mm Length limit after use 64 0 mm Cooling system Nexus 500 COOL SYS 6 ...

Page 335: ...m is guaranteed by the accurate machining and cleaning of the components as they are fitted in any case ceramic seals are subjected to a running in period During this period 1 000 1 500 km there may be small leaks through draining holes which remain visible on the aluminium crankcase This phenomenon is particularly visible there where the hole is more exposed Quasar and Master In such cases we rec...

Page 336: ...rm up Manually check when there is an abrupt increase in temperature at the exit of the radiator cold hous ing N B THERE SHOULD BE A SLIGHT AND GRADUAL HEATING CAUSED BY A SMALL PASSAGE ON THE THERMOSTAT TO THE OFF POSITION Specific tooling 020460Y Scooter diagnosis and tester Check the temperature read by the diagnostic tester Thermostat opening start 80 C If opening occurs at different temperatu...

Page 337: ... water and thermostat cool down Progressively heat the water keeping the thermostat immersed by the wire Check the opening temperature when the thermostat releases from the wire Opening starting temperature 82 C Specific tooling 020331Y Digital multimeter 020151Y Air heater Warm up until the thermostat is completely open N B HEATING SHOULD BE GRADUAL N B AVOID CONTACT BETWEEN THERMOSTAT AND CONTAI...

Page 338: ...eck the system outside seals as described above YES go to 2 NO go to 3 2 Check the head gasket seal see Thermal unit and timing system chapter If water leaks are detected in the engine oil inspect the pad on the head cooling circuit 3 Fix any damaged seals Oil in the fluid 1 Oil into the coolant YES go to 2 2 Check the head gasket seal see Thermal group and timing system chapter Cooling system Nex...

Page 339: ...INDEX OF TOPICS CHASSIS CHAS ...

Page 340: ...in of the gas shock absorber and the 2 chassis fixing screws Remove the under saddle light control button Rear handlebar cover Release the 3 locking tabs of the rear handlebar cover shown in the figure using a screwdriver and paying attention not to damage the paintwork Remove the 5 mounting screws of the rear han dlebar cover N B WHEN INSTALLING THE CENTRE SCREW IS A METAL SCREW THE OTHER 4 ARE P...

Page 341: ...4 retaining screws of the front han dlebar cover with the handlebar proper Remove the 4 pressure indicator lights from the warning light group pulling them downwards Instrument panel Remove the upper shield back plate Loosen the 5 nuts of 10 mm holding the instru ment panel Nexus 500 Chassis CHAS 3 ...

Page 342: ...r of the expansion tank To remove the left hand light assembly remove the screw located in the left hand storage com partment Remove the light disconnecting the electric con nector from the light and the complete lamp holder of the position light N B THE TWO REAR ADJUSTMENT SCREWS SHOWN IN THE FIGURE ARE ADJUSTED DUR ING ASSEMBLY OF THE LIGHT AND MUST NOT BE ALTERED Chassis Nexus 500 CHAS 4 ...

Page 343: ...he battery Remove the complete cover extracting it from top Legshield Remove the mirrors Remove the windscreen with support Remove the front light groups Remove the top counter shield Remove the bottom counter shield Remove the 2 screws under the rearview mirrors Remove the central screw without non threaded rim located behind the front headlight Remove the 4 screws 2 per side accessible from the ...

Page 344: ...f the windshield support and the 4 side retainers of the front shield Knee guard Remove the centre union Remove the 4 lateral screws 2 on each side in dicated in the figure Press the shield back plate forward to allow ac cess to the socket on the frame of the key switch Turn the frame in anticlockwise direction it may be necessary to use pliers disengaging the lock ing teeth shown in the figure Ch...

Page 345: ...screws on the front of the scooter holding the plate Remove the handlebar retaining bolt unscrewing upwards and pushing towards the lower shield back plate Remove the cap of the expansion tank and the rubber gasket using a screwdriver or pliers Disconnect the complete upper shield back plate from the lower section paying particular attention to the tab located under the glove box left hand side On...

Page 346: ...ing of the immobiliser antenna Loosen the 2 hex socket head screws and re move the complete switch From the underside it is possible to loosen the 3 retaining screws and to release the 2 locking tabs to raise the mounting plate of the steering lock strut The latter has a retaining tab with cylindrical teeth that cannot be replaced Chassis Nexus 500 CHAS 8 ...

Page 347: ...lower retainer of the wheel housing Remove the upper fixing screw of the wheel housing to permit movement In order to remove the wheel housing it is necessary to remove the front brake hose to the tank and combination with the splitter Taillight assy Remove the sides Remove the top central screw Move the headlight away and remove the lamp holder turning it by 30 in counter clockwise di rection Nex...

Page 348: ...age the stud bolts from the support tails Footrest Remove the centre union Remove the side fairings Remove the mat of the footrest Remove the screws indicated in the figure Remove the screw shown in the figure Remove the footboard and the side Remove the screw shown in the figure to remove the front footrest Chassis Nexus 500 CHAS 10 ...

Page 349: ...ocated below the air inlet union of the filter Remove the rear fixings and the complete side License plate holder Remove the lower cover Remove the four retaining screws 2 per side and disconnect the electrical connectors In order to access the licence plate bulb it is suf ficient to remove the two retaining screws of the rear cover from the support and to pull out the complete bulb holder Nexus 5...

Page 350: ...n in the figure Loosen the two screws shown in the figure Loosen the two retainers shown in the figure and remove the complete air filter Remove the general fuse Disconnect the battery housing from its metallic support and remove the complete filter housing Electric characteristic Fuse 30A Chassis Nexus 500 CHAS 12 ...

Page 351: ...e Remove the retainer of the mudguard strut rein forcement plate to remove the complete mud guard Helmet bay Remove the side panels Remove the six upper clamping screws Remove the 2 lateral retaining screws with the central covers Nexus 500 Chassis CHAS 13 ...

Page 352: ...move the complete underseat compartment Helmet compartment This is to inform you that starting from frame no ZAPM3510000005247 the old helmet compart ment item no 975974 has been superseded by item no 621886 see drawing The new helmet compartment features the following modifications A reinforcement clamp added to avoid deformations caused in the eventuality of a possible interference with the seat...

Page 353: ...own in the figure Remove the 3 hex screws shown in the figure N B THE OTHER 3 SCREWS HAVE ONLY AN AES THETIC FUNCTION Remove the flap the gasket the second flap and the second gasket Remove the fuel port Remove the 2 bands fixing the filler to the tank Extract the 2 top tubes the left tube is the over flow the right one is the tank aeration Nexus 500 Chassis CHAS 15 ...

Page 354: ...O PRESS LIGHTLY ONTO THE LINES AND TO PUSH THE CROWN TO WARDS THE PUMP AND THEN TO MAINTAIN PRESSURE ON THE CROWN AND TO PULL THE LINES UPWARDS Remove the plate supporting bracket for the horn and voltage regulator by loosening the two retain ing screws shown in the figure in order to release the two lower retainers of the wheel housing Remove the tank through the front lower part of the scooter F...

Page 355: ...egulator by loosening the two fixing screws shown in the figure in order to release the two lower retainers of the wheel housing Remove the upper fixing screw of the wheel housing to permit movement Prepare a container to collect the coolant Remove the feed and return hoses from the ex pansion tank Remove the coolant feed and return hoses from the radiator Remove the retaining screws of the radiat...

Page 356: ...2 hex socket head screws and then the passenger handgrips on the left and right Flyscreen Remove the 3 hex socket head screws when reassembling pay attention to insert the longest screw in the middle position then remove the windshield complete from the rubber lips Chassis Nexus 500 CHAS 18 ...

Page 357: ...ge the 7 retaining tabs 3 with the shield back plate 4 with the shield Once the 4 lateral tabs have been released it is sufficient to separate the upper part from the lower part and to pull it carefully upwards Pilot lights kit Remove the handlebar cover Remove the three screws shown in the figure then pull the complete group from the front han dlebar cover Nexus 500 Chassis CHAS 19 ...

Page 358: ... Remove the elastic strap and the battery cover Lower cover Remove the two rear screws shown in the figure Remove the 4 bottom screws shown in the figure and the complete bottom cover Chassis Nexus 500 CHAS 20 ...

Page 359: ...INDEX OF TOPICS PRE DELIVERY PRE DE ...

Page 360: ...teering tube 45 50 Upper steering ring nut 36 39 Lower steering ring nut 10 13 tighten and loosen by 90 Cover retaining screws Electrical system Electric System Main switch Headlamps high beams low beams side taillights front and rear and relevant warning lights Adjusting the headlights according to the regulations currently in force Front and rear brake light buttons and relevant bulb Turn indica...

Page 361: ...EK IMMEDIATE MEDICAL ATTENTION THE BATTERIES PRODUCE EXPLOSIVE GAS KEEP THEM AWAY FROM NAKED FLAMES SPARKS AND CIGARETTES IF THE BATTERY IS CHARGED IN A CLOSED PLACE TAKE CARE TO ENSURE ADEQUATE VENTILATION ALWAYS PROTECT YOUR EYES WHEN WORKING CLOSE TO BATTERIES KEEP OUT OF THE REACH OF CHILDREN CAUTION NEVER USE FUSES WITH A CAPACITY HIGHER THAN THE RECOMMENDED CAPACITY USING A FUSE OF UNSUITABL...

Page 362: ...peration Engine Check for correct general operation and make sure there is no unusual noise Other Check documents Check chassis No and engine No Check tool kit License plate assembly Check locks Check tyre pressures Installation of mirrors and any accessories CAUTION NEVER EXCEED THE RECOMMENDED INFLATION PRESSURES OR TYRES MAY BURST CAUTION CHECK AND ADJUST TYRE PRESSURE WITH TYRES AT AMBIENT TEM...

Page 363: ...INDEX OF TOPICS TIME TIME ...

Page 364: ...evoted to the time necessary to carry out repairs For each operation the description code and time envisages are specified Engine ENGINE Code Action Duration 1 001001 Engine to chassis Replace ment Time Nexus 500 TIME 2 ...

Page 365: ...Crankcase CRANKCASE Code Action Duration 1 001100 Oil seal clutch side Re placement 2 001133 Engine crankcase Replace ment 3 001153 Crankcase half gasket Re placement Nexus 500 Time TIME 3 ...

Page 366: ...Crankshaft CRANKSHAFT Code Action Duration 1 001117 Crankshaft Replacement 2 001098 Countershaft Replacement Time Nexus 500 TIME 4 ...

Page 367: ...Cylinder assy CYLINDER GROUP Code Action Duration 1 001002 Cylinder piston Replace ment 2 001154 Pin ring piston assembly Service 3 001129 Chain tensioner Service and Replacement Nexus 500 Time TIME 5 ...

Page 368: ...01045 Valves Replacement 2 001049 Valves Adjustments 3 001056 Head gasket Replacement 4 001126 Head Replacement 5 001083 Thermistor Replacement 6 005116 revolution timing sensor Re placement 7 007012 Coolant bleed valve Re placement Time Nexus 500 TIME 6 ...

Page 369: ...Rocker arms support assy ROCKING LEVER SUPPORT UNIT Code Action Duration 1 001044 Camshaft Replacement 2 001148 Rocking lever valve Re placement Nexus 500 Time TIME 7 ...

Page 370: ...Cylinder head cover HEAD COVER Code Action Duration 1 001089 Head cover Replacement 2 001093 Spark plug Replacement 3 001088 Head cover gasket Replace ment Time Nexus 500 TIME 8 ...

Page 371: ...01123 Oil filter Replacement 4 001124 By pass valve Replacement 5 001057 Thermostat Replacement 6 001062 Water pump command shaft Replacement 7 001150 Flywheel cover gasket Re placement 8 001160 Minimum oil pressure sensor Replacement 9 007011 By pass manifold thermo stat drain valve Replace ment Nexus 500 Time TIME 9 ...

Page 372: ...ven pulley DRIVEN PULLEY Code Action Duration 1 001022 Clutch Replacement 2 001012 Driven pulley Overhaul 3 001110 Driven pulley Replacement 4 001155 Clutch bell housing Re placement Time Nexus 500 TIME 10 ...

Page 373: ... 2 001051 Belt Timing chain Replace ment 3 001112 Oil pump change 4 001125 Chain guide pads change 5 001071 Start up pinion Replace ment 6 001020 Starter motor Replacement 7 001102 Net oil filter Replacement Cleaning 8 003064 Engine oil change Nexus 500 Time TIME 11 ...

Page 374: ...EDUCTION GEAR ASSEMBLY Code Action Duration 1 001010 Geared reduction unit Serv ice 2 001156 Gear reduction unit cover Replacement 3 003065 Gear box oil Replacement 4 004125 Rear gear shaft Replace ment Time Nexus 500 TIME 12 ...

Page 375: ...de Action Duration 1 001086 Driving half pulley Replace ment 2 001011 Driving belt Replacement 3 001006 Driving pulley Service 4 001141 Belt anti flapping roller Re placement 5 001066 driving pulley Replacement Nexus 500 Time TIME 13 ...

Page 376: ...ation 1 001065 Internal transmission cover Replacement 2 001096 External transmission cover Replacement 3 001131 Transmission air intake Re placement 4 001135 Transmission cover bearing Replacement 5 001170 Air manifold replacement Time Nexus 500 TIME 14 ...

Page 377: ...TO FLYWHEEL Code Action Duration 1 001173 Rotor replace 2 001067 Stator Replacement 3 001058 Flywheel Replacement 4 001104 Start up freewheel Replace ment 5 001151 Start up driven gearing Re placement Nexus 500 Time TIME 15 ...

Page 378: ... Code Action Duration 1 001013 Intake manifold change 2 001047 Injector Replacement 3 001166 Throttle body Replacement 4 004122 Cleaner Throttle body union Replacement 5 001171 Throttle body Service clean ing Time Nexus 500 TIME 16 ...

Page 379: ...R Code Action Duration 1 001009 Muffler Replacement 2 001092 Exhaust manifold Replace ment 3 001095 Muffler guard Replacement 4 001136 Exhaust emissions Adjust ment 5 004169 Muffler guard Replacement Nexus 500 Time TIME 17 ...

Page 380: ...Air cleaner AIR CLEANER Code Action Duration 1 001015 Air filter box change 2 001014 Air filter Replacement Cleaning 3 001074 Oil vapour recovery pipe Re placement Time Nexus 500 TIME 18 ...

Page 381: ...Frame FRAME Code Action Duration 1 004001 Frame replace 2 004146 Front frame Replacement 3 001032 Engine support pin Replace ment Nexus 500 Time TIME 19 ...

Page 382: ...stand SIDE CENTRAL STAND Code Action Duration 1 004004 Stand Replacement 2 004102 Side stand Replacement 3 005079 Side stand switch Replace ment 4 004171 Stand support plate Re placement Time Nexus 500 TIME 20 ...

Page 383: ...Replace ment 2 005091 Turn indicator glass Re placement 3 005067 Front direction indicator bulb Replacement 4 004064 Front shield Replacement 5 004149 Shield central cover Re placement 6 004065 Shield back plate Replace ment 7 005080 Front fuse holder Replace ment Nexus 500 Time TIME 21 ...

Page 384: ... Code Action Duration 1 004011 Central chassis cover Re placement 2 004104 Left side cover Replace ment 3 004105 Right side cover Replace ment 4 004079 Rear footrest Replacement 5 004143 Footrest support replace Time Nexus 500 TIME 22 ...

Page 385: ...udguard MUDGUARDS Code Action Duration 1 004167 Grill radiator cover replace 2 004009 Rear mudguard Replace ment 3 004002 Front mudguard change 4 003087 Wheel housing Replace ment Nexus 500 Time TIME 23 ...

Page 386: ...uel tank FUEL TANK Code Action Duration 1 004005 Fuel tank replace 2 004170 Tank filler neck Replace ment 3 004168 Fuel filler flap Replacement 4 004109 Fuel tank breather replace Time Nexus 500 TIME 24 ...

Page 387: ...on 1 004018 Handlebar front section Re placement 2 004019 Handlebar rear section Re placement 3 005129 Warning light group Re placement 4 004156 Glove box flap Replace ment 5 005038 Instrument panel warning light bulbs Replacement Nexus 500 Time TIME 25 ...

Page 388: ...e placement 4 002060 Complete gas command Replacement 5 002059 Right hand grip Replace ment 6 003059 Counterweight Replace ment 7 002063 Throttle control transmission Replacement 8 003061 Accelerator transmission Adjustment 9 002024 Front brake pump replace 10 002071 Left hand grip Replacement 11 002088 Integral brake pump Re placement Time Nexus 500 TIME 26 ...

Page 389: ...Seat SADDLE Code Action Duration 1 004003 Saddle Replacement 2 004150 Saddle shock absorber Re placement Nexus 500 Time TIME 27 ...

Page 390: ...ric saddle opening de vice Replacement 3 002083 Saddle opening transmission Replacement 4 002092 Seat locking transmission replacement 5 004054 Saddle lock catch Replace ment 6 005072 Immobilizer antenna re placement 7 005126 Saddle opener receiver re placement Time Nexus 500 TIME 28 ...

Page 391: ...urn indicator glass Re placement 5 005031 Licence plate light bulb Re placement 6 004136 License plate holder support Replacement 7 005030 Rear headlight cable unit Replacement 8 005048 Licence plate holder Re placement 9 005032 Transparent licence plate cover replace 10 005028 Rear light assembly glass Replacement 11 005066 Rear light bulbs Replace ment Nexus 500 Time TIME 29 ...

Page 392: ...FRONT LIGHTS Code Action Duration 1 005002 Front headlamp replace 2 005008 Front headlamp bulbs re place 3 005044 Front lights cable unit re place Time Nexus 500 TIME 30 ...

Page 393: ...ngs Re placement 6 003047 Front tyre replace 7 003063 Tyre pressure check 8 004123 Front wheel Replacement Grease tone wheel or drive Please take note that the code has been intro duced 900001 Tone wheel drive greasing 15 Never mistake the codes 002011 movement sen sor replacement and 005089 tone wheel replace ment in the event of noise of the indicated components The grease recommended is TUTE Ne...

Page 394: ... Rear wheel REAR WHEEL Code Action Duration 1 001016 Rear wheel Replacement 2 001017 Rear wheel rim replace 3 002070 Rear brake disc Replace ment 4 003063 Tyre pressure Check 5 003077 Muffler rear shock absorber support arm Service 6 004126 Rear wheel tyre Replace ment 7 002028 Rear wheel hub Replace ment 8 004052 Bumper Replacement Time Nexus 500 TIME 32 ...

Page 395: ...Fuel pump FUEL PUMP Code Action Duration 1 004073 Fuel pump Replacement 2 004137 Injector pump pipe Replace ment Nexus 500 Time TIME 33 ...

Page 396: ...Code Action Duration 1 005001 Electrical system Replace ment 2 005054 Fuse holder Replacement 3 005052 Fuse 1 Replacement 4 005114 Electrical system Service 5 005130 Electric control management device Replacement Time Nexus 500 TIME 34 ...

Page 397: ...unit Re placement 2 005009 Voltage regulator Replace ment 3 005117 Electrical fan remote control Replacement 4 005088 Emergency stop remote con trol Replacement 5 005096 Injection components remote control Replacement 6 005003 Horn Replacement Nexus 500 Time TIME 35 ...

Page 398: ... coil Replacement 3 005007 Battery change 4 005046 Battery cover change 5 005073 Immobilizer decoder Re placement 6 005011 Start up remote control switch Replacement 7 005128 Diode group replacement 8 001094 Spark plug cap Replace ment 9 005024 Main fuse replacement Time Nexus 500 TIME 36 ...

Page 399: ...nstrument panel Replace ment 2 005014 Odometer assembly re placement 3 005083 Board computer replace ment 4 003074 Handlebar right control Re placement 5 003075 Handlebar left control Re placement 6 005082 Instrument unit wiring re placement Nexus 500 Time TIME 37 ...

Page 400: ...uration 1 004016 Helmet compartment re place 2 005033 Glove box light switch Re placement 3 005026 Helmet compartment light Replacement 4 004142 Plug socket Replacement 5 005027 Helmet compartment bulb support Replacement Time Nexus 500 TIME 38 ...

Page 401: ...ing Replacement 3 004068 Passenger handgrip Re placement 4 004159 Plates Stickers Replace ment 5 004036 Lower chassis cover Re placement 6 004012 Rear side panels 2 Re placement 7 004075 Mat Replacement 8 004015 Footrest Replacement 9 004056 Upper rear light cover Re placement Nexus 500 Time TIME 39 ...

Page 402: ...eplace 2 003010 Front suspension service 3 003076 Fork housing replacement 4 003079 Fork stem Replacement 5 003048 Fork oil seal Replacement 6 003073 Steering clearance Adjust 7 003002 Steering fifth wheels change 8 004119 Upper steering bearing re placement Time Nexus 500 TIME 40 ...

Page 403: ...SPENSION Code Action Duration 1 003085 Suspension strut Replace ment 2 003007 Rear shock absorber Re placement 3 004120 Rear suspension linkage Replacement 4 003086 Suspension strut support re placement Nexus 500 Time TIME 41 ...

Page 404: ... support Replace ment 3 007001 Expansion tank Replace ment 4 007024 Expansion tank cap Re placement 5 007019 Coolant return pipe replace ment 6 007013 Expansion tank radiator connecting hose Replace ment 7 001052 Coolant and air bleed re placement 8 007022 Coolant delivery pipe Re placement Time Nexus 500 TIME 42 ...

Page 405: ...mp pipe de vice Replacement 6 002085 Integral front brake pipes 7 002089 Integral breaking device Re placement 8 002090 Integral brake fluid and bleed ing system Replacement 9 002039 Front brake calliper Re placement 10 002040 Front brake calliper Service 11 002007 Front brake pads replace 12 003070 Front brake pads Wear and tear check 13 002002 Rear brake pads replace 14 003071 Rear brake pads We...

Page 406: ...n Duration 16 002068 Rear calliper Service Windscreen WINDSHIELD Code Action Duration 1 004028 Windshield glass Replace ment 2 004101 Windscreen Replacement 3 004117 Top fairing Replacement Time Nexus 500 TIME 44 ...

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Summary of Contents for Nexus 500

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Gilera Nexus 500, Workshop Manual, Page: 111 / 406

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Summary of Contents for Nexus 500

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