Malaguti 500 cc 4T Service Manual Download Page 8

Page: 8 / 78

10/07

Specification

Desc./Quantity

0.15 mm

0.010 mm

0.10 mm

Specification

Desc./Quantity

Cat. 1

Standard diameter: 40.010 ÷ 40.016

Cat. 2

Standard diameter: 40.016 ÷ 40.022

Piston rings

*Fit rings "2" and "3" with the word "TOP" facing upwards.

** Position the openings in the rings as shown here.

***Value "A" of sealing ring inside the cylinder.

Check the size of the sealing ring opening:

Compression ring: 0.15 ÷ 0.35 mm. Max. value 0.5 mm

Oil scraper ring: 0.25 ÷ 0.50 mm. Max. value 0.65 mm

Rings/housing coupling clearances:

Carefully clean the sealing ring housings.

Place a thickness gauge between the ring and the hou-
sing as shown in the drawing and check the coupling cle-
arances.

Top ring
Standard coupling clearance: 0.01÷0.06 mm

Maximum clearances allowed after use: 0.10 mm

Intermediate ring
Standard coupling clearance: 0.02÷0.07 mm

Maximum clearances allowed after use: 0.10 mm

Oil scraper ring
Standard coupling clearance: 0.01÷0.06 mm

Maximum clearances allowed after use: 0.10 mm

Replace the piston if clearances exceed the maximum
limits specified in the table.

MAX. ADMISSIBLE DISPLACEMENT

Crankcase - crankshaft - connecting rod

Diameter of crankshaft bearings.

Measure the capacity on both axes x-y.

CRANKSHAFT

Crankshaft alignment

Specific tooling

020335Y
Magnetic support for dial gauge

Summary of Contents for 500 cc 4T

Page 1: ......

Page 2: ...ce operations to be carried out on the engine in order to make sure the topics the technical and safety concepts are clearly understood and the manual can be used as a sure reference text All checks maintenance repairs or replacements of spare parts etc are to be performed by skilled and expert technical personnel with specific experience in state of the art technology and full knowledge of the qu...

Page 3: ...and possibly laying them out according to the sequence in which they are to be used Always keep the work area neat and clean When tightening screws or nuts start with the larger diameter or inner fasteners and tighten them in progressive pulls using a criss cross pattern The torque settings specified in the manual refer to the final torque which must be attained progressively by steps Preferably u...

Page 4: ...4 1234 1234 1234 1234 1234 1234 1234 1234 1234 1234 1234 1234 1234 1234 1234 1234 1234 1234 1234 1234 1234 1234 1234 1234 1234 1234 1234 1234 1234 1234 1234 1234 1234 1234 1234 1234 1234 1234 1234 1234 1234 1234 1234 FLYWHEEL AND STARTING 33 Removing the starter motor Removing the flywheel magneto 34 Inspecting the flywheel components Starter gear rim 36 Intermediate gear Refitting the free wheel ...

Page 5: ... Quantity Type Single cylinder 4 stroke with double spark plug Bore x Stroke 94 x 71 mm Cubic capacity 493 cm Compression ratio 10 5 1 Timing system Four valves single overhead camshaft chain driven Valve clearance Inlet 0 15 mm Outlet 0 15 mm Engine idle speed 1 500 100 rpm Start up Electric Lubrication Engine lubrication with trochoidal pump inside the crankcase oil filter and pressure adjustmen...

Page 6: ...ASSEMBLY Tightening Torques THERMAL UNIT AND TIMING SYSTEM TRANSMISSION COVER CRANKCASE AND CRANKSHAFT FINAL REDUCTION Apply a preliminary torque of 7 Nm in a crossed sequence Tighten by 90 in a crossed sequence Tighten again by 90 in a crossed sequence Name Torque in Nm Spark plug 12 14 Head fixing stud bolts Head fixing nuts 10 12 Exhaust intake head fixing nuts 10 12 Head lubrication control je...

Page 7: ...rews 0 7 0 9 Screws fixing oil pump to the crankcase 5 6 Name Torque in Nm Flywheel fixing nut 115 125 Stator retainers 8 10 Blow by recovery duct fixing screws 3 4 Screw fixing freewheel to flywheel 13 15 Stator cable harness guide bracket screws 3 4 FLYWHEEL COVER LUBRICATION Overhaul data This section provides the main information for scooter servicing Assembly clearances cylinder piston assy H...

Page 8: ...refully clean the sealing ring housings Place a thickness gauge between the ring and the hou sing as shown in the drawing and check the coupling cle arances Top ring Standard coupling clearance 0 01 0 06 mm Maximum clearances allowed after use 0 10 mm Intermediate ring Standard coupling clearance 0 02 0 07 mm Maximum clearances allowed after use 0 10 mm Oil scraper ring Standard coupling clearance...

Page 9: ...TING ROD The value of the M fixture axial clearance is acceptable within the range of 0 20 0 60 mm Description Dimensions Transmission side shoulder E 1 0 025 Half shaft transmission side F 20 9 Connecting rod G 22 Flywheel side half shaft H 19 6 Flywheel side shoulder I 1 8 0 025 Complete crankshaft L 65 5 0 0 05 0 10 0 15 0 0 05 0 10 0 05 ...

Page 10: ...HICKER THE MORE THE PLANE FORMED BY THE PISTON TOP PROTRUDES FROM THE PLANE FORMED BY THE CYLINDER HEAD ON THE OTHER HAND THE MORE THE PISTONTOPISRECESSEDINTOTHECYLINDERTOPPLANE THESMALLER THE GASKET THICKNESS N B VALUES INDICATED WITH REFER TO PISTON CROWN RECESSES WITH RESPECT TO THE CYLINDER PLANE N B DISTANCE A MUST BE MEASURED WITHOUT ANY GASKET FITTED AT B RECOMMENDED LUBRICATING TABLE BASE ...

Page 11: ...plastic transmission cover Using a screwdriver remove the driven pulley axle cover near the bottom 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 USING DIFFERENT WRENCHES SUCH AS A CONVENTIONAL POLYGONAL BUSH MAYDAMAGETHEHEXA...

Page 12: ...ews shown in the figure to remove the conveyor filter Removing the driven pulley shaft bearing Remove the transmission cover Remove the seeger ring Place transmission cover on a wood surface and use the special tool so that it is adequately supported Pull out the bearing using the special tool N B BELL MUST BE PLACED INTO THE TRANSMISSION COVER CLOSE TO THE BEARINGSEATANDTHEWOODEN SURFACE SINCEWIT...

Page 13: ...OTATEFREELY REPLACETHECOMPLETEROLLER Place the bearing onto the special tool with a little grease to prevent it from coming out Install the new bearing using the special tool N B PROPERLYSUPPORT THE OUTSIDE COVERTOPREVENTDAMAGINGTHE PAINTEDSURFACE Specific tooling 020376Y Adaptor handle 020358Y 37x40 mm adaptor 020439Y 17 mm guide Installation of belt anti vibration roller Install the anti flappin...

Page 14: ... ventilation holes Move the rear stop screw in abutment against the fixed driven pulley as shown in the figure THETOOLSHOULDBEFIRMLY SECUREDINAVICEUSINGTHE SPECIALTOOL DONOTTIGHTENTHE REARSCREWTOOMUCHASTHISCOULD CAUSEANIRREVERSIBLETOOL DEFORMATION USINGTHESPECIAL55 MM WRENCH REMOVETHEFASTENING RINGNUT LOOSENTHETOOLSCREWAND DISASSEMBLETHEDRIVENPULLEY UNIT CLUTCH SPRINGWITHSHEATH Specific tooling 02...

Page 15: ...pull out the ball bearing N B PROPERLYSUPPORT THE PULLEYTO PREVENTDAMAGINGTHETHREADING Specific tooling 020376Y Adaptor handle 020456Y Ø 24 mm adaptor 020363Y 20 mm guide Inspecting the clutch Check the thickness of the clutch mass friction material Characteristic Minimum thickness permitted 1 mm The masses must not show traces of lubricants Otherwise check the driven pulley unit seals N B UPONRUN...

Page 16: ... guide 001467Y002 Driver for OD 73 mm bearing Inspecting the driven sliding half pulley Check that the belt contact surface is free from wear Remove the 2 inside sealing rings and the 2 outside O rings Measure the movable half pulley bushing inside diameter Characteristic Maximum admissible diameter 50 05 mm Standard diameter 50 00 mm Refitting the driven half pulley bearing Install a new roller b...

Page 17: ... of the spring while it is relaxed Characteristic Standard length 125 5 mm Admissible limit after use 120 mm Refitting the clutch Prepare the special tool as for removal Preassemble the driven pulley unit with the drive belt according to its direction of rotation Insert the driven pulley unit the spring with sheath and clutch into the tool Specific tooling 020444Y Tool for fitting removing the dri...

Page 18: ...clamps of the special tool onto the pulley so that the splines are completely engaged Then insert the tool so as to insert the stud bolts on the ring into the holes obtained onto the tool itself Tighten the two tool fixing screws also manually Loosen the central nut Remove the spring washer and the flat washer Remove the fixed driving half pulley Remove the bushing connection washer Move the belt ...

Page 19: ...ct 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 Assembly the half pulley with the roller contrast plate and sliding blocks Inspecting the rolle...

Page 20: ...h the guide bushing of the moving driving pulley Remove the flat washer and the spring washer as shown in the figure Insert the nut in the original position nut side in contact with the belleville washer Turn the central pulley nut to horizontally align the holes and install the special tool N B CHECKTHATTHESTOPWRENCHTOOLIS EASILYINSERTEDINTOTHEPULLEYANDIN THEENGINECRANKCASE Specific tooling 02047...

Page 21: ...ners Lock the four M8 retainers Lock the 7 M6 retainers Insert the washers on the driven pulley shaft N B INSERTTHESMALLERWASHERFIRST THENTHELARGERONE Insert the flanged nut Prepare the torque wrench for LHS locking hexagon wrench Tighten the driven pulley shaft fastening nut using an offset wrench N B DUE TO THE HIGH TIGHTENING TORQUE USING DIFFERENT WRENCHES SUCH AS A CONVENTIONALPOLYGONALBUSH M...

Page 22: ... drainage cap located under the engine Remove the 7 fastening screws Remove the hub cover and the relevant gasket Removing the wheel axle Remove the countershaft Remove the wheel axis complete with gear Removing the hub bearings Check all bearings wear clearance and noise In case of anomalies proceed as follows To remove the gear shaft bearing on the engine crankcase use the following parts Specif...

Page 23: ... housing outside diameter 47 mm Support the hub cover using the column kit Pull out the bearing using the special tool Specific tooling 020476Y Stud bolt set 001467Y006 Extraction pliers for 20 mm bearings 001467Y007 Driver for OD 54 mm bearing 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 020477...

Page 24: ...020376Y Adaptor handle 020358Y 37x40 mm adaptor 020364Y 25 mm guide Inspecting the hub shaft Check that the 3 shafts exhibit no wear or deformation 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 mm Connection diameter for wheel shaft B diameter 30 mm C diameter 15 mm Connect...

Page 25: ...20364Y 25 mm guide Heat the intermediate gear bearing seat Insert the intermediate shaft bearing using the special tool N B PLACEITWITHTHEBALLSFACINGTHE HUB THIS APPLIES TO BEARINGS WITH PLASTICCAGE Specific tooling 020376Y Adaptor handle 020359Y 42 x 47 mm adaptor 020363Y 20 mm guide Heat the gear shaft bearing seat on the crankcase Insert the gear shaft bearing in the upper crankcase seat using ...

Page 26: ...ing 020151Y Air heater 020476Y Stud bolt set Insert the intermediate shaft bearing on the cover using the special tool N B PLACEITWITHTHEBALLSFACINGTHE HUB THIS APPLIES TO BEARINGS WITH PLASTICCAGE Specific tooling 020376Y Adaptor handle 020360Y 52 x 55 mm adaptor 020363Y 20 mm guide Heat the gear shaft bearing seat from the cover outside Insert the gear shaft bearing on the cover using the specia...

Page 27: ...areful 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 products Q8 ZC 90 rear oil hub SAE 80W 90 Oil that exceeds the API GL3 specifications Characteristic Quantity approx 250 cc Locking torques N m Rear hub cover screws 24 27 Flywheel cover Remove the three bands sho...

Page 28: ...e the flywheel cover with the relevant gasket and the cooling system sleeve support N B THESCREWSAREOF4DIFFERENT LENGTHS NOTETHERELEVANT POSITIONS Removing the flywheel cover components Loosen the six mounting screws and remove the water pump cover Remove the by pass and the relevant spring Remove the oil pump seal BECAREFULTOPREVENTSLIPPAGE OFTHEBY PASSVALVEANDOFTHE RELEVANTSPRING REMOVETHECOVERA...

Page 29: ...ith bulkhead Remove the blow by reed valve with the relevant sealing gasket Unscrew the fastening screw and remove the gas outlet union with the relevant O ring Check that the mounting surface of the crankcaseisnotwornordeformed Checkthattheby passvalveseat thetorque limiterandthewaterpumpshaftarefreefrom wear Characteristic By pass housing hole diameter 13 9 mm Connection diameter for start up ge...

Page 30: ... Ω Ω Ω Ω Check the earth insulation of each phase If a fault is discovered carry out a close check of the cable harness that 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 Refitting the stator Install the stator assembly together with the wirin...

Page 31: ...channels Oil pressure sensor feeding duct Oil vapour decantation chamber 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 torque Insert the spring and the by pass piston on the flywheel cover N B LUBRICATETHEBY PASSVALVE Locking torques N m Stator cable harness gu...

Page 32: ... clamps N B TIGHTENTHECLAMPSUSING APPROPRIATEPLIERS PAYING ATTENTIONNOTTOCONSTRICTTHE HOSES BUTALSO TAKING CARE TO TIGHTENTHECLAMPSSUFFICIENTLY 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 Q8 FORMULA EXCEL Engine oil SAE 5W 40 API SL ACEA A3 JASO MA Synthetic oil Lubricat...

Page 33: ...WATER PUMP COVERINSTALLED Install the flywheel cover on the engine paying attention to avoid interference between the stator and rotor FAILURETOOBSERVETHIS INSTRUCTIONMAYRESULTIN DESTRUCTIONOFTHECERAMIC MAGNETS THEINTERMEDIATEBOLTSFORTHE REMAININGMOUNTINGPOINTSWITH THEEXCEPTIONOFTHEBOLTFORTHE MANIFOLD SUPPORT SHOWN IN THE FIGURE ARESLIGHTLYLONGER Tho lock the 14 retaining bolts of the cover to the...

Page 34: ...bsorption N B THEDECLAREDRPMVALUEISTHATINDICATEDBYTHETESTER THERPMREADINGIS NOT THE REALONE BUT IS VALID FOR DIAGNOSTIC PURPOSES Electric characteristic Absorption at trailing speed 80 120 A Revolution speed approx 300 400 rpm N B IFTHETRAILINGSPEEDOFTHE CRANKSHAFTISLOWANDCOMBINED WITHSTRANGENOISE CHECKTHE FREEWHEELOFTHETORQUELIMITER SEETHE FLYWHEELANDSTARTER SYSTEM CHAPTER BECAREFULNOTTODAMAGETHE...

Page 35: ...block retain plate and the start up rim Align the holes obtained on the flywheel with the crankcase housing to allow the introduction of the special tool Tighten the bushing of the flywheel lock tool on the removing tool threading Insert the special tool as shown in the figure making sure that the pins are perfectly inserted into the previously aligned holes and that it is perfectly abutted and al...

Page 36: ...ut and extract the flywheel with the start up rim Remove the crankshaft key Insert the special removing tool Using a 27 mm wrench and a 19 mm bushing release the flywheel Specific tooling 020467Y Flywheel extractor To remove the start up rim from the freewheel it is necessary to turn it clockwise and pull it out Remove the freewheel from the flywheel by loosening the 6 fastening screws SINCETHEFRE...

Page 37: ...r or abnormal impressions on the rollers of the freewheel and on the surface of the starter ring gear hub Check the hub outside diameter Characteristic Hub outside diameter Diameter 45 665 mm N B IFTHEFAULTSDISCOVEREDAFFECTTHEHUB REPLACETHESTARTERRINGGEARAND FREEWHEEL IF ONLYTHE BUSHING IS WORN IT IS POSSIBLE TO REPLACE ONLYTHE COMPLETE START UPRIM INTHATCASE CHECKALSOTHEDIAMETERANDTHESURFACEOFTHE...

Page 38: ...the six clamping screws in criss cross fashion to the prescribed torque Locking torques N m Screw fixing freewheel to flywheel 13 15 Oil the free wheel rollers Also check the shaft diameter on the flywheel cover and on the engine crankcase Characteristic Shaft diameter on the flywheel cover 12 mm Shaft diameter on the engine crankcase 12 mm N B THE TORQUE LIMITER IS PROVIDED WITH 4GEARSTHATHAVETHE...

Page 39: ...rting at the same time Insert the intermediate gear with torque limiter Lubricate the inside bushing and the starter ring gear hub surface 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 ...

Page 40: ...l lock wrench Tighten the flywheel lock nut to the prescribed torque Locking torques N m Flywheel fixing nut 115 125 Install the chain guide retain plate tightening the 3 screws to the prescribed torque N B BEFORETIGHTENINGTHESCREWS MOVE THE START UPRIM IN CONTACT WITHTHECRANKCASEANDCHECKTHAT IT IS FREE TOROTATE IN ANTICLOCKWISEDIRECTION Locking torques N m Chain guide sliding block retain plate f...

Page 41: ...tappet cover with relevant gasket Remove the flywheel cover the flywheel and the torque limiter Removing the intake manifold Remove the 3 mounting screws Remove the intake manifold unit Removing the timing system drive Verify that the intake valves are closed Remove the central screw and the valve lifting device mass stop bell using the special tool Specific tooling 020565Y Flywheel lock calliper ...

Page 42: ... the reference marks on the timing chain rim with those on the head Loosen the central screw on the tensioner first Unscrew the 2 fastening screws and remove the tensioner with relevant gasket Remove the timing belt rim from the camshaft Remove the timing belt rim Removing the cam shaft Unscrew the 3 fastening screws and remove camshaft retaining bracket N B REMOVINGTHEFASTENINGSCREWS MAYBEDIFFICU...

Page 43: ...ture sensor N B THESENSORCONTROLSBOTH INJECTIONANDTHEANALOGUE INSTRUMENTONTHEPANEL TOCHECK THIS COMPONENT SEE THE INJECTION CHAPTER Remove the 2 fastening nuts on the head on the exhaust and on the intake side Remove the two M6 screws into the distribution channel and the M6 screw on the spark plug side with the thermostat support N B IFNECESSARY THEHEADMAYBE REMOVED WITH THE CAMSHAFT PINS ROCKING...

Page 44: ...OLANT Removing the valves Using the appropriate tool fitted with an adapter remove the cotters washers springs and valves Specific tooling 020382Y Valve cotters equipped with part 012 removal tool 020382Y012 bush valve removing tool ARRANGE THE VALVES SOAS TO RECOGNISETHEORIGINAL POSITIONONTHEHEAD FLYWHEELSIDE AND TRANSMISSION SIDE Remove the oil guards using the special tool Specific tooling 0204...

Page 45: ...SE PAPER ORACLOTH TO CLOSE THE CYLINDERHOUSINGMOUTHONTHE CRANKCASETOPREVENTSLIPPAGEOF ONEOFTHEPINLOCKINGRINGSINTO THECASE Remove the piston sealing rings and the oil scraper CAUTION NOTE THEASSEMBLYPOSITIONS OFTHELININGSTOPREVENTINVERTING THEPOSITIONINCASEOFREUSE N B BECAREFULNOTTODAMAGETHE SEALINGRINGSDURINGREMOVAL Inspecting the small end Using a bore gauge measure the connecting rod small end d...

Page 46: ...in the position shown in the figure N B SEE PAG 6 FOR THE SIZES OF THE PISTONANDTHECYLINDER PISTON COUPLINGCLEARANCES Using a bore meter measure the cylinder inner diameter at a given height according to the directions shown in the figure Characteristic B 43 mm Standard diameter 94 mm nominal value Check that coating is free from flakes Check that the head matching surface exhibits no deformations...

Page 47: ...ing opening Compression ring 0 15 0 35 mm Max value 0 5 mm Oil scraper ring 0 25 0 50 mm Max value 0 65 mm Oil scraper ring 0 25 0 50 mm Max value 0 65 mm Rings housing coupling clearances Carefully clean the sealing ring housings Place a thickness gauge between the ring and the housing as shown in the drawing and check the coupling clearances Top ring Standard coupling clearance 0 01 0 06 mm Maxi...

Page 48: ...ing into the special tool with the opening in the position indicated on the tool S left D right Install the pin lock using the key shown in the figure Specific tooling 020470Y Pin retainers installation tool N B THE TOOLFOR INSTALLING THE STOP RINGSMUSTBEUSEDMANUALLY USINGAHAMMERMIGHTDAMAGE THE STOPS HOUSING Place the wrist pin stop ring into position using a punch ...

Page 49: ...nkshaft 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 Correctly identify the cylinder base gasket thickness to keep the correct compression ratio Remove the special tool and the cylinder N B IFDEVIATIONS ORRECESSESORPROJECTIONS CLOSETOTHECHANGEOF CATE...

Page 50: ...shown in the figure Lubricate the components with engine oil The engine uses the first compression lining with an L section Refitting the cylinder Insert the cylinder base gasket with the thickness determined above Using the fork and the band clamp install the cylinder as shown in the figure N B BEFOREINSTALLINGTHECYLINDER CAREFULLYBLOWTHELUBRICATION DUCTANDLUBRICATETHECYLINDER LINER CHECKTHEPRESE...

Page 51: ...alings Visually inspect the valve sealing surface DONOTREVERSETHEFITTING POSITIONS OF THE VALVES RIGHT LEFT If the sealing surface of the valve is found to be interrupted at one or more points or is not flat replace the valve Insert the valves into the cylinder head Alternatively check the intake and exhaust valves The test is carried out by filling the manifold with petrol and checking that the h...

Page 52: ...ve and valve guide Check the deviation of the valve stem by resting it on a V shaped abutment and measuring the extent of the deformation by a comparator Characteristic Limit values admitted 0 01 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 Check that there are no signs of wear on the su...

Page 53: ... the guide see figure TOAVOIDSCORINGTHECONTACTSURFACE DONOTKEEPROTATINGTHEVALVE WHENNOLAPPINGCOMPOUNDISLEFT CAREFULLYWASHTHECYLINDERHEAD AND THE VALVES WITHASUITABLE PRODUCT FOR THE TYPE OF LAPPING COMPOUND BEINGUSED DO NOT REVERSE THE FITTING POSITIONS OF THE VALVES RIGHT LEFT Inspecting the springs and half cones Check that the upper and lower supporting spring washers the cotters and the oil se...

Page 54: ...ht STANDARD DIAMETER MINIMUM ADMISSIBLE DIAMETER STANDARD HEIGHT ADMISSIBLE LIMITS Refitting the valves Place the valve spring support washers on the head Alternately insert the 4 oil guards using the special tool Lubricate the oil guards and the valve guides Specific tooling 020306Y Punch for assembling valve seal rings Fit the valves the springs and the spring retaining washers Using the appropr...

Page 55: ... block and the articulated register plate is free from wear In case of wear replace the component Refitting the head and timing system components Insert the chain guide sliding block Insert the two centring dowels between head and cylinder Install the head gasket N B THE FIGURE SHOWS THE INSERTION POSITION OF THE TWO CENTRING DOWELSBETWEENHEADANDCYLINDER THEDIRECTIONOFINSTALLATIONFORTHE GASKETISFO...

Page 56: ...ith its spacer tightening the bolt to the prescribed torque using the recommended product Recommended products Loctite 243 Medium strength threadlock Medium Loctite 243 threadlock Insert pins and rocking levers on the flywheel side Lubricate the two rocking levers through the holes at the top Locking torques N m Spark plug 12 14 Nm Locking torques N m Tensioner sliding block fixing screw 10 14 Tig...

Page 57: ...bed torque being careful not to damage the inside hexagon Using the TORX wrench remove the timing check cap Insert the belt on the camshaft control timing rim Insert the timing rim on the camshaft checking that the references are aligned N B DURINGTHESTROKECHECK KEEPTHE BELTTENSIONEDBYPRESSINGONTHE TIGHTENERCOMPARTMENTSIDE Keeping the belt slightly pulled turn the crankshaft using the driving pull...

Page 58: ...aft 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 product N B THEBELLTIMINGISENSUREDBYTHE COUNTERWEIGHTMASSFASTENING SCREWHEAD Recommended products Loctite 243 Medium strength threadlock Medium Loctite 243 threadlock Install the return spring and load it b...

Page 59: ...asis 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 the value actually activated on the engine by means of the stroboscopic light Sp...

Page 60: ...rocal sliding of the cover surface with the head surface Tighten the remaining 4 screws in a crossed sequence 3 4 5 6 N B CHECKTHEPROPERPOSITIONOFTHE GASKET Locking torques N m Tappet cover fixing screws 7 9 Repeat for the reference between driving pulley and transmission housing Replace the inspection cap on the flywheel side Connect the diagnostic tester Start the engine Select the menu on the p...

Page 61: ...emove the flywheel with the starting system following the instruction given in Flywheel and Starting system Remove the thermal unit cylinder head piston as described in the Thermal unit and timing system chapter Before opening the crankcase check the crankshaft axial clearance For this purpose use a plate e g the special tool and a support with special tool comparator Specific tooling 020262Y Cran...

Page 62: ...USHINGSUPPORTCANBELEFTIN THEFLYWHEELSIDEHALF CRANKCASE Remove the 14 crankcase coupling screws N B THEFASTENINGSCREWSAREOF3 DIFFERENTLENGTHS NOTETHEIR CORRECTPOSITION Removing the oil pump and countershaft control gear To remove the control gear loosen the 4 fastening screws Remove the gear only if actually required THE SCREWS HAVEA COUNTERSUNKHEADANDTHEIR THREADINGISLOCKEDBYLOCTITE BE CAREFULNOTT...

Page 63: ...Remove the special tool and extract the countershaft with the control gear Remove the bearing from the transmission side half crankcase using the special tool Specific tooling 001467Y008 Extraction pliers for ø 17 mm bearings 001467Y007 Driver for OD 54 mm bearing Remove the fastening nut with relevant washer Upturn the half crankcase Remove the bearing from the flywheel side half crankcase using ...

Page 64: ...fter greasing the guide seat Install the new bearing on the half crankcase using the special tool N B IFABEARINGWITHPLASTICCAGEIS USED KEEPTHEBALLSVISIBLEFROM THECRANKCASEINTERNALSIDE Specific tooling 020376Y Adaptor handle 020359Y 42 x 47 mm adaptor 020439Y 17 mm guide Specific tooling 020376Y Adaptor handle 020359Y 42 x 47 mm adaptor 020439Y 17 mm guide Insert a new bearing on the special tool a...

Page 65: ... mm Check that shim adjustment is free from scratches N B IN CASE OF NEW UTILISATION MAINTAIN THE FIRST FITTING POSITION Specific tooling 020074Y Support base for checking crankshaft alignment If the crankshaft crankcase axial clearance is higher than the standard value and the crankshaft exhibits no irregularity the problem is caused by wear or by a wrong machining on the engine crankcase MAX ADM...

Page 66: ...section Thermal unit and timing system See also Cylinder assy and timing system Inspecting the crankcase halves Before proceeding to check the crankcase halves thoroughly clean the all surfaces and oil ducts For the transmission side half crankcase special attention should be given to the bushings to the cooling jet on the transmission side see figure and to the lubrication duct N B THEJETISFEDTHR...

Page 67: ...heck on the crankshaft Inspecting the crankshaft plain bearings To obtain a good bushing lubrication it is necessary to have both an optimal lubricating pressure 4 bar and a good oil flow rate the bushings must be correctly positioned so as not to obstruct the oil supply channels The main bushings are comprised of two half bearings one containing holes and channels for lubrication and the other so...

Page 68: ...gs for housing a category 1 crankshaft and a countershaft with centre to centre distance A Complete FC2 type crankcase equipped with bushings for housing a category 2 crankshaft and a countershaft with centre to centre distance A Complete FC3 type crankcase equipped with bushings for housing a category 1 crankshaft and a countershaft with centre to centre distance B Complete FC4 type crankcase equ...

Page 69: ...ert the special timing tool in the hole on the countershaft Specific tooling 020471Y Pin for countershaft timing N B WHENINSERTINGTHESHAFTONTHEHALF CRANKCASE BECAREFULNOTTODAMAGE THEMAINBEARINGWITHTHETHREADEDTANGOFTHECRANKSHAFTANDWITHTHE TIMINGCONTROLTOOTHEDPINION Refitting the crankshaft Check that the oil pump and countershaft control gear are free from deformations or dents Replace if required ...

Page 70: ...THECYLINDER PLANE TOENSUREBETTERSEALINGPERFORMANCE Install the thermal unit cylinder head piston as described in section Thermal unit and timing system Install the flywheel with start up control as described in the Flywheel and start up chapter Install the flywheel cover with the cooling system sleeves as described in the Flywheel cover chapter Install the complete driving pulley the transmission ...

Page 71: ...ation pressure 4 bar Specification Desc Quantity Type Trochoidal Rotor thickness 8 mm Assembly clearances Lobe ends 0 05 0 008 mm Outside rotor radial clearance 0 05 0 12 mm Rotor axial clearance 0 025 0 065 mm Product Description Specifications Q8 FORMULA EXCEL Engine oil SAE 5W 40 API SL ACEA A3 JASO MA Synthetic oil Specification Desc Quantity Overhaul 1 7 l Oil and filter replacement 1 5 l Lub...

Page 72: ...dge filter and both are installed on the flywheel cover so that the seal of the filter is subject to the pressure of the circuit The by pass located before the cartridge filter improves the operating conditions for the filter proper particularly with cold oil The filter is equipped with an anti cavitation valve and a pressure relief valve the latter intervenes when the filtering element causes a p...

Page 73: ... may result in a blockage in the ducts of the throttle body In order to signal low oil pressure in the circuit a pressure switch is used located immediately after the oil filter outlet The lubrication circuit does not include the countershaft its lubrication comes from the oil transported by the gearing or by the centrifugal effect of the crankshaft The same applies to the piston or the pin but in...

Page 74: ...he Flywheel cover chapter YES go to 14 NO go to 15 14 Check whether there is an irregular clearance on the crankshaft axial clearance see the Crankcase and crankshaft chapter radial clearance especially in the direction of the cylinder axis clearance according to the direction of rotation with the connecting rod in quadrature YES go to 16 NO go to 17 15 Replace the faulty components Flywheel cover...

Page 75: ...SCOSITY AHIGHERVISCOSITYCAUSESANINCREASEOFTHESYSTEMPRESSURE 1 If oil consumption is higher than 250 g 1000 km on run in engine proceed as follows AHEAD go to 2 2 Check the presence of oil at the recovery duct on the filter box YES go to 3 NO go to 4 3 Check the unidirectional reed valve and the decantation chamber drainage hole YES go to 5 NO go to 4 4 Check the thermal unit seals piston rings val...

Page 76: ...eassemble the rotors in the pump body keeping the two reference marks visible Insert 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 between the rotors in the position shown in the figure Characteristic Admissible limit clearance 0 012 mm Ch...

Page 77: ...f scoring or wear on the oil pump cover If non conforming values or signs of wear are found replace the pump Fit the pump cover in the position that permits the crankcase fixing screws to be aligned Tighten the two fastening screws to the prescribed torque Locking torques N m Oil pump cover screws 0 7 0 9 Insert the oil pump with gear Insert the 2 retaining screws through the slots on the gear and...

Page 78: ... side half crankcase Install the special tool in the position shown in the figure Specific tooling 020479Y Countershaft lock wrench Keep the countershaft in position and insert the washer 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 Medium Loctite 243 threadlock Locking torque...

Search results

Summary of Contents for 500 cc 4T

Reviews:

Malaguti 500 cc 4T, Service Manual, Page: 8 / 78

Search results

Summary of Contents for 500 cc 4T

Reviews: