Yamaha SR125 1997 Service Manual Download Page 236

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8-2

POOR IDLE SPEED PERFORMANCE

TRBL

SHTG

IGNITION SYSTEM
Battery

Improperly charged battery

Faulty battery

Fuse

Burnt out, improper connection

Spark plug

Improper plug gap

Worn electrodes

Wire between terminals broken

Improper heat range

Faulty spark plug cap

Ignition coil

Broken or shorted primary / secondary coil

Faulty high tension cord

Broken ignition coil body

Ignition system

Faulty C.D.I. unit

Faulty pick up coil

Broken magneto woodruff key

Switch

Faulty main switch

Faulty “ENGINE STOP” switch

Faulty front and / or rear brake switch

Faulty sidestand switch

Wiring

Loose battery terminal

Loose coupler connection

Improperly grounded

Broken wireharness

SR901000

POOR IDLE SPEED PERFORMANCE

POOR IDLE SPEED PERFORMANCE
Carburetor

Improperly returned starter plunger

loose or clogged pilot jet

Damaged carburetor joint

Improperly tightened carburetor joint clamp
hose

Improperly adjusted idle speed
(Pilot screw), (Throttle stop screw)

Improperly adjusted throttle cable

Flooded carburetor

Air filter

Clogged air filter element

Ignition system

Faulty spark plug

Faulty high tension cord

Faulty C.D.I. unit

Faulty pick up coil

Faulty ignition coil

Valve system

Improperly adjusted valve clearance

Summary of Contents for SR125 1997

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Page 3: ... SR125 SERVICE MANUAL 1996 by Yamaha Motor Co Ltd 1st Edition September 1996 All rights reserved Any reprinting or unauthorized use without the written permission of Yamaha Motor Co Ltd is expressly prohibited ...

Page 4: ...ve all its models Modifications and signif icant changes in specifications or procedures will be forwarded to all authorized Yamaha dealers and will appear in future aditions of this manual where applicable Designs and specifications are subject to change without notice IMPORTANT INFORMATION Particularly important information is distinguished in this manual by the following notations The Safety Al...

Page 5: ...To help identify parts and clarify procedure steps there are exploded diagrams at start of each removal and disassembly section 1 An easy to see exploded diagram 4 is provided for disassembly and assembly jobs 2 Numbers 5 are given in the order of jobs in the exploded diagram A number that is enclosed by a circle indicates a disassembly step 3 An explanation of jobs and notes is presented in an ea...

Page 6: ... appearing in the text 9 Possible to maintain with engine mounted 10 Filling fluid 11 Lubricant 12 Special tool 13 Tightening 14 Wear limit clearance 15 Engine speed 16 Ω V A Illustrated symbols 17 to 22 in the exploded dia grams indicate the types of lubricants and lu brication points 17 Apply engine oil 18 Apply gear oil 19 Apply molybodenum disulfide oil 20 Apply wheel bearing grease 21 Apply l...

Page 7: ...NERAL INFORMATION SPECIFICATIONS PERIODIC INSPECTION AND ADJUSTMENT ENGINE OVERHAUL CARBURATION CHASSIS ELECTRICAL TROUBLESHOOTING GEN INFO 1 SPEC 2 3 ENG 4 CARB 5 CHAS 6 ELEC 7 TRBL SHTG 8 INSP ADJ INDEX ...

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Page 9: ...R 1 1 MODEL LABEL 1 1 IMPORTANT INFORMATION 1 2 PREPARATION FOR REMOVAL PROCEDURES 1 2 REPLACEMENT PARTS 1 2 GASKETS OIL SEALS AND O RINGS 1 2 LOCK WASHERS PLATES AND COTTER PINS 1 3 BEARINGS AND OIL SEALS 1 3 CIRCLIPS 1 3 CHECKING OF CONNECTIONS 1 4 HOW TO USE THE CONVERSION TABLE 1 5 SPECIAL TOOLS 1 6 ...

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Page 11: ...The frame serial number 1 is stamped into the right side of the frame EB100030 ENGINE SERIAL NUMBER The engine serial number 1 is stamped into the crankcase Designs and specifications are subject to change without notice MODEL LABEL The model label 1 is affixed under the seat This information will be needed to order spare parts ...

Page 12: ... disassembly clean all parts and place them in trays in the order of disas sembly This will speed up assembly and al low for the correct installation of all parts 6 Keep all parts away from any source of fire NB101010 REPLACEMENT PARTS 1 Use only genuine Yamaha parts for all re placements Use oil and grease recom mended by Yamaha for all lubrication jobs Other brands may be similar in function and...

Page 13: ... are visible When installing oil seals apply a light coating of lightweight lithium base grease to the seal lips Oil bearings liberally when installing if ap propriate 1 Oil seal Do not use compressed air to spin the bear ings dry This will damage the bearing sur faces 1 Bearing EB101050 CIRCLIPS 1 Check all circlips carefully before reassemb ly Always replace piston pin clips after one use Replac...

Page 14: ...he lead to check that it will not come off 5 If the terminal comes off bend up the pin 1 and reinsert the terminal into the connector 6 Connect Connector The two connectors click together 7 Check for continuity with a tester If there is no continuity clean the terminals Be sure to perform the steps 1 to 7 listed above when checking the wireharness For a field remedy use a contact revitalizer avail...

Page 15: ...0 08 in CONVERSION TABLE METRIC TO IMP Known Multiplier Result Torque m kg m kg cm kg cm kg 7 233 86 794 0 0723 0 8679 ft lb in lb ft lb in lb Weight kg g 2 205 0 03527 lb oz Distance km hr km m m cm mm 0 6214 0 6214 3 281 1 094 0 3937 0 03937 mph mi ft yd in in Volume Capacity cc cm3 cc cm3 lit liter lit liter 0 03527 0 06102 0 8799 0 2199 oz IMP liq cu in qt IMP liq gal IMP liq Miscellaneous kg ...

Page 16: ...ese tools are used when removing or installing the rocker arm shafts 90890 01268 Ringnut wrench This tool is used to loosen and tighten the exhaust and steering ringnut 90890 01311 Valve adjusting tool This tool is necessary for adjusting valve clearance 90890 01312 Fuel level gauge This gauge is used to measure the fuel level in the float chamber 90890 01367 90890 01400 Fork seal driver weight Fo...

Page 17: ... needed for detecting engine rpm 90890 03141 Timing light This tool is necessary for checking ignition timing 90890 04019 90890 04108 Valve spring compressor Attachment These tools are used when removing or installing the valve and the valve spring 90890 04064 Valve guide remover 6 mm This tool is used to remove the valve guide 90890 04065 Valve guide reamer 6 mm This tool is used to rebore the va...

Page 18: ... lapper This tool is used for removing and installing the lifter and for lapping the valve 90890 06754 Ignition checker This instrument is necessary for checking the ignition system components 90890 85505 Yamaha bond No 1215 This sealant bond is used for crankcase mating surface etc ...

Page 19: ...ECIFICATIONS 2 1 MAINTENANCE SPECIFICATIONS 2 4 ENGINE 2 4 CHASSIS 2 10 ELECTRICAL 2 13 GENERAL TORQUE SPECIFICATIONS 2 15 LUBRICATION POINT AND GRADE OF LUBRICANT 2 16 ENGINE 2 16 CHASSIS 2 17 LUBRICATION DIAGRAM 2 18 CABLE ROUTING 2 20 ...

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Page 21: ...type Cylinder arrangement Displacement Bore stroke Compression ratio Compression pressure STD Starting system Lubrication system Air cooled 4 stroke SOHC Forward inclined single cylinder 0 124 L 124 cm3 57 0 48 8 mm 10 0 1 1 200 kPa 12 0 kg cm2 12 0 bar at 1 000 r min Electric starter Wet sump Oil type or grade Engine oil API SE or higher grade Periodic oil change With oil filter replacement Total...

Page 22: ...3 500 Constant mesh 5 speed Left foot operation 36 16 2 250 31 21 1 476 27 24 1 125 25 27 0 926 23 29 0 793 Chassis Frame type Caster angle Trail Diamond 26 75 90 mm Tire Type Size front rear Manufacture front rear Type front rear Tube type 3 00 17 45P 3 50 16 52P INOUE INOUE 8F 8RA Tire pressure cold tire Maximum load except motorcycle Loading condition A front rear Loading condition B front rear...

Page 23: ... Coil spring Oil damper Coil spring Oil damper Wheel travel Front wheel travel Rear wheel travel 120 mm 78 mm Electrical Ignition system Generator system Battery type Battery capacity C D I C D I magneto 12N 7 3B 12 V 7 AH Headlight type Bulb type Bulb wattage quantity Headlight Auxiliary light Tail brake light Flasher light Meter light High beam indicator Neutral indicator TURN indicator 12 V 36 ...

Page 24: ...n Cam chain type No of links Cam chain adjustment DID 25SH 104 ENDLESS Manual SSS SSS Rocker arm rocker armshaft Rocker arm inside diameter Rocker shaft outside diameter Rocker arm to rocker armshaft clearance 12 000 X 12 018 mm 11 985 X 11 991 mm 0 009 X 0 033 mm 12 036 mm 11 950 mm SSS Valve valve seat valve guide Valve clearance cold IN EX 0 05 X 0 09 mm 0 11 X 0 15 mm SSS SSS Valve dimensions ...

Page 25: ...SSS Clockwise Counterclockwise 33 5 mm 35 2 mm SSS SSS SSS SSS 2 5_ 1 5 mm 2 5_ 1 5 mm SSS SSS Piston Piston to cylinder clearance Piston size D Piston over size 1st Piston over size 2nd Measuring point H Piston off set Piston off set direction Piston pin bore inside diameter Piston pin outside diameter 0 025 X 0 045 mm 56 960 X 56 975 mm 57 25 mm 57 50 mm 7 0 mm 0 5 mm IN side 15 002 X 15 013 mm ...

Page 26: ...t Drive axle runout limit SSS SSS 0 08 mm 0 08 mm Carburetor Type I D mark Main jet M J Main air jet M A J Jet needle J N Needle jet N J Cut away C A Pilot outlet P O Pilot jet P J Bypass 1 B P 1 Pilot screw P S Valve seat size V S Starter jet 1 G S 1 Starter jet 2 G S 2 Float height F H Engine idle speed Intake vacuum CO Oil temperature Y24P 4WP 10 102 ø1 3 4C9A 3 5 2 600 2 25 0 8 38 1 0 2 ø2 0 6...

Page 27: ...inder Crankcase left and right Crankcase cover left Crankcase cover left Crankcase cover right Drive sprocket cover Starter clutch Kick crank Primary drive gear Clutch spring Clutch boss Push lever axle Push lever adjuster Screw Bolt Bolt Screw Bolt Bolt Bolt Nut Bolt Nut Bolt Nut Nut Bolt Screw Screw Bolt Screw Bolt Screw Screw Screw Screw Screw Bolt Bolt Screw Screw Screw Screw Screw Bolt Bolt N...

Page 28: ...d size Q ty Tightening torque Remarks g size y Nm mSkg Drive sprocket Shift cam Segment Shift pedal Pick up coil Neutral switch Stator coil Starter motor Bolt Screw Bolt Screw Screw Screw Screw M6 M6 M6 M6 M10 M4 M6 2 1 1 4 1 6 1 10 12 8 7 20 3 7 1 0 1 2 0 8 0 7 2 0 0 3 0 7 ...

Page 29: ...2 9 MAINTENANCE SPECIFICATIONS SPEC Tightening sequence Cylinder head Crankcase Item Standard Limit ...

Page 30: ... 135 mm Fork oil 15 WT or equivalent SSS SSS 321 mm SSS SSS SSS SSS SSS SSS SSS SSS 0 2 mm Rear suspension Shock absorber stroke Spring free length Fitting length Spring rate K1 K2 Stroke K1 K2 65 mm 178 5 mm 198 mm 18 3 N mm 1 83 kg mm 21 6 N mm 2 16 kg mm 0 X 30 mm 30 X 65 mm SSS 173 mm SSS SSS SSS SSS SSS Front wheel Type Rim size Rim material Rim runout limit radial lateral Spoke wheel 17 1 60...

Page 31: ...4 mm 6 2 mm 6 2 mm 12 7 mm 30 16 mm 25 4 mm DOT 4 or DOT 3 SSS SSS 3 5 mm 0 8 mm 0 8 mm SSS SSS SSS SSS Rear brake Type Drum inside diameter Shoe thickness Shoe spring free length Leading trailing 110 mm 4 mm 50 5 mm SSS 111 mm 2 mm SSS Brake lever Brake lever free play at lever end 2 X 5 mm SSS Brake pedal Brake pedal free play Brake pedal position 20 X 30 mm 0 mm SSS SSS Clutch lever Clutch leve...

Page 32: ...nk an fuel cock Rear flasher and stay Sidestand bolt Sidestand nut Rear footrest left Front wheel axle Rear wheel axle and nut Brake caliper and front fork Brake disc and front wheel Driven sprocket and clutch hub Brake caliper bleed screw Meter gear and meter cable Brake cam lever Front wheel axle pinch bolt M10 M10 M8 M25 M4 M10 M6 M10 M12 M10 M8 M8 M8 M8 M8 M12 M10 M10 M8 M8 M8 M6 M12 M8 M8 M10...

Page 33: ...cap Type Resistance Resin type 10 kΩ SSS SSS Charging system Type Model manufacturer Standard output Stator coil resistance color C D I magneto 4WP YAMAHA 14 V 9 A 5 000 r min 0 48 X 0 72 Ω at 20_C White White SSS SSS SSS SSS SSS Rectifier regulator Model manufacturer Type regulator No load regulated voltage Capacity rectifier Withstand voltage SH553D SHINDENGEN Semi conductor short circuit type 1...

Page 34: ...ng resistance MS5D 191 JIDECO 100 A 3 9 X 4 7 Ω at 20_C SSS SSS SSS Horn Model manufacturer Maximum amperage YF 12 NIKKO 2 5 A SSS SSS Flasher relay Type Model manufacturer Flasher frequency Condenser type FR2204 MITUBA 85 cycle min SSS SSS SSS Circuit breaker Type Main Reserve Fuse 20 A 1 pcs 20 A 1 pcs SSS SSS SSS ...

Page 35: ...k To avoid warpage tighten multi fastener assemblies in a crisscross fashion in progressive stages until full torque is reached Unless otherwise specified torque specifica tions call for clean dry threads Components should be at room temperature A Distance across flats B Outside thread diameter A Nut B Bolt General torque specifications Nut Bolt Nm mSkg 10 mm 6 mm 6 0 6 12 mm 8 mm 15 1 5 14 mm 10 ...

Page 36: ...ton pin Piston piston ring Buffer boss Valve stem valve guide IN EX Valve stem end IN EX Rocker arm shaft Cam and bearing camshaft Rocker arm inner surface Crankcase mating surfaces Yamaha bond No 1215 O ring all Starter idle gear thrust surfaces Starter clutch outer roller Starter wheel gear inner surface Push rod Primary driven gear inner surface Push lever axle Transmission gear inner surface S...

Page 37: ...ar wheel hub Rear brake shoe plate camshaft and pivoting pin Pivoting points brake pedal shaft and frame Sidestand sliding surface mounting bolt Pivoting point centerstand Tube guide throttle grip inner surface Brake lever bolt master cylinder sliding surface Clutch lever bolt cable sliding surface Steering lock sliding surface Gear unit speedometer Chain guard inner surface swigarm insert surface...

Page 38: ...2 18 1 Rocker arm IN 2 Rocker shaft 3 Rocker arm EX 4 Camshaft 5 Oil pump 6 Push lever LUBRICATION DIAGRAM SPEC LUBRICATION DIAGRAM ...

Page 39: ...2 19 1 Oil pump 2 Oil filter 3 Crankshaft 4 Main axle 5 Drive axle 6 Oil strainer LUBRICATION DIAGRAM SPEC ...

Page 40: ...ad left 15 Horn lead 16 Flasher relay 17 Handlebar switch lead right 18 Front brake switch lead 19 Front flasher right 20 Meter lead 21 Front flasher lead right 22 Wireharness 1 Front brake switch lead 2 Brake hose 3 Handlebar switch lead right 4 Throttle cable 5 Clutch cable 6 Clutch switch lead 7 Handlebar switch lead left 8 Speedometer cable 9 Clamp 10 Main switch coupler 11 Front flasher left ...

Page 41: ... the headlight body And pass them the right inside of the front fork D Pass the brake hose to the holder E Clamp the clutch cable to the down tube of the frame CABLE ROUTING SPEC 1 Clamp 2 Wireharness 3 High tension cord 4 Collar 5 Ignition coil 6 Ground lead 7 Ignition coil lead 8 Brake hose 9 Clutch cable 10 Rear brake switch 11 Starting circuit cut off relay 12 Battery breather hose ...

Page 42: ...arness 19 Speedometer cable 20 Cable holder 21 Brake hose holder 22 Cable holder 23 Brake hose 24 Starter motor lead 25 Sidestand switch 26 Rectifier Regulator lead CABLE ROUTING SPEC 1 Neutral switch lead 2 Pickup coil lead 3 C D I unit 4 Rear flasher lead right 5 Rear flasher lead left 6 Tail Brake light lead 7 C D I magneto lead 8 Thermostatic switch lead 9 Clamp 10 Sidestand switch lead 11 Sta...

Page 43: ...2 23 CABLE ROUTING SPEC 1 Air filter case 2 Battery 3 Swingarm 4 Battery breather pipe 5 Lid 6 Air filter case drain pipe A Pass the air filter case drain pipe inside the swingarm ...

Page 44: ...SPEC ...

Page 45: ...ENSIONER ADJUSTMENT 3 13 CLUTCH ADJUSTMENT 3 13 AIR FILTER CLEANING 3 14 EXHAUST SYSTEM INSPECTION 3 15 CHASSIS 3 17 FRONT BRAKE ADJUSTMENT 3 17 REAR BRAKE ADJUSTMENT 3 17 BRAKE FLUID LEVEL INSPECTION 3 19 BRAKE PAD INSPECTION 3 20 BRAKE SHOE INSPECTION 3 20 BRAKE LIGHT SWITCH ADJUSTMENT 3 20 AIR BLEEDING 3 21 DRIVE CHAIN SLACK ADJUSTMENT 3 22 STEERING HEAD INSPECTION 3 24 FRONT FORK INSPECTION 3 ...

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Page 47: ...e if necessary 4 Air filter Clean Replace if necessary 5 Carburetor Check idle speed starter operation Adjust if necessary 6 Fuel line Check fuel hose for cracks or damage Replace if necessary 7 Engine oil Replace Warm engine before draining 8 Engine oil filter Replace 9 Front brake Check operation fluid leakage see NOTE Correct if necessary Rear brake Check operation Adjust if necessary Clutch Ch...

Page 48: ...Check specific gravity Check breather pipe for proper operation Correct if necessary It is recommended that these items be serviced by a Yamaha dealer Medium weight wheel bearing grease bearing type Lithium soap base grease bush type Brake fluid replacement 1 When disassembling the master cylinder or caliper cylinder replace the brake fluid Normally check the brake fluid level and fill the fluid a...

Page 49: ...emoval Side cover left Side cover right Seat Fuel pipe Fuel tank 1 1 1 1 1 Remove the parts in order Reverse the removal procedure for instal lation Disconnect the fuel pipe set the fuel cock lever OFF position NOTE SIDE COVER SEAT AND FUEL TANK INSP ADJ SIDE COVER SEAT AND FUEL TANK ...

Page 50: ...TANK section 2 Remove SSpark plug cap 1 SSpark plug SValve cover intake side 2 SValve cover exhaust side 3 3 Remove STiming check plug with O ring 1 SCenter plug with O ring 2 4 Measure SValve clearance Out of specification Adjust Valve clearance cold Intake valve 0 05 0 09 mm Exhaust valve 0 11 0 15 mm Measurement steps SRotate the crankshaft counterclockwise to align the slit a on the rotor with...

Page 51: ...ve adjusting tool 90890 01311 Hold the adjuster to prevent it from moving and tighten the locknut Measure the valve clearance If the clearance is incorrect repeat above steps until specified clearance is obtained 6 Install Valve cover intake side 1 O ring 2 Valve cover exhaust side 3 O ring 4 A Intake side B Exhaust side 7 Install Spark plug Timing check window screw 1 with O ring Center plug 2 wi...

Page 52: ... screw 2 in or out until the specified idling speed is obtained Turning in Idling speed is increased Turning out Idling speed is decreased 5 Adjust Throttle cable free play Refer to THROTTLE CABLE ADJUST MENT section YP303032 THROTTLE CABLE ADJUSTMENT Prior to adjusting the throttle cable free play the engine idling speed should be adjusted 1 Check Throttle cable free play a Out of specification A...

Page 53: ...ng speed to change EB303040 SPARK PLUG INSPECTION 1 Remove Spark plug cap Spark plug Before removing the spark plug use com pressed air to blow away any dirt accumu lated in the spark plug wells to prevent it from falling into the cylinder 1 Check Spark plug type Incorrect Replace Standard spark plug DR8EA NGK 2 Inspect Electrode 1 Wear damage Replace Insulator 2 Abnormal color Replace Normal colo...

Page 54: ...l ground connec tions are tight 1 Remove Timing check plug 2 Attach Timing light 1 Engine tachometer 2 to the spark plug lead Timing light 90890 03141 Engine tachometer 90890 03113 3 Check Ignition timing Checking steps Start the engine and let it warm up for several minutes Let the engine run at the specified speed Engine idling speed 1 250 1 350 r min Visually check the stationary pointer a to v...

Page 55: ...ated in the spark plug well to prevent it from falling into the cylinder 5 Attach Compression gauge 1 Compression gauge 90890 03081 Adaptor 90890 04082 6 Measure Compression pressure If it exceeds the maximum pressure allowed Inspect the cylinder head valve surfaces and piston crown for carbon deposits If it is below the minimum pressure Squirt a few drops of oil into the affected cylinder and mea...

Page 56: ...EL INSPECTION 1 Stand the motorcycle on a level surface Make sure the motorcycle is upright when in specting the oil level 2 Start the engine and let it warm up for a few minutes 3 Turn off the engine 4 Inspect Engine oil level Oil level should be between maximum 1 and minimum 2 marks Oil level is below the minimum mark Add oil up to the proper level RECOMMENDED ENGINE OIL Refer to the chart for s...

Page 57: ...ntil the oil settles before in specting the oil level SR303082 ENGINE OIL REPLACEMENT 1 Start the engine and let it warm up for several minutes 2 Turn off the engine and place a container un der the engine 3 Remove Oil filler plug 1 Drain plug 2 Drain the crankcase of its oil 4 Loosen Bolt 1 oil filter cover lower 5 Drain the crankcase of its oil If the oil filter is to be replaced during this pro...

Page 58: ...h oil filter change 1 1 L Without oil filter change 1 0 L Refer to ENGINE OIL LEVEL INSPECTION section 8 Inspect SOil flow Inspection steps SSlightly loosen the oil check bolt 1 SStart the engine and keep it idling until the oil begins to seep from the oil check bolt If no oil comes out after one minute turn the engine off so it will not seize SCheck oil passages and oil pump for damage or leakage...

Page 59: ... adjust er end 2 Not flush Adjust 3 Adjust STiming chine tension Adjustment steps SLoosen the locknut 1 STurn the adjuster 2 in or out until the rod end 3 is flush with the adjuster end STighten the locknut 1 Locknut 30 Nm 3 0 mSkg 4 Install SCap EB303093 CLUTCH ADJUSTMENT 1 Check SClutch cable free play a Out of specification Adjust Free play clutch lever 10 15 mm at clutch lever end ...

Page 60: ...lay with the other adjuster on the clutch lever holder Lever side SLoosen the locknut 3 STurn the adjuster 4 in or out until the specified free play is obtained Turning in Free play is increased Turning out Free play is decreased STighten the locknut 3 SR303123 AIR FILTER CLEANING 1 Remove SSide cover right SAir filter element holder SAir filter element 1 SPlate 2 Never operate the engine without ...

Page 61: ...it Never use low flash point solvents such as gasoline to clean the air filter element Such solvents may cause a fire or an explosion 4 Apply the recommended oil to the entire sur face of the filter and squeeze out the excess oil The element should be wet but not drip ping Recommended oil Engine oil 5 Install SPlate 1 SAir filter element 2 SAir filter element holder SSide cover right T EXHAUST SYS...

Page 62: ...3 16 EXHAUST SYSTEM INSPECTION INSP ADJ 1 2 2 Check STightening torque Bolt 12 Nm 1 2 mSkg Nut 20 Nm 2 0 mSkg ...

Page 63: ...s increased Tighten the locknut Make sure that there is no brake drag after adjusting the front brake lever free play A soft or spongy feeling in the brake lever can indicate the presence of air in the brake system This air must be removed by bleed ing the brake system before the motorcycle is operated Air in the brake system will con siderably reduce braking performance and could result in loss o...

Page 64: ...e locknut 3 Check SBrake pedal free play a Out of specification Adjust Free play Brake pedal 20 30 mm at brake lever end 4 Adjust SBrake pedal free play Adjustment steps STurn the adjuster 1 in or out until the specified free play is obtained Turning in Free play is decreased Turning out Free play is increased Make sure that there is no brake drag after adjusting the brake pedal height and the fre...

Page 65: ...OT 4 or DOT 3 For a correct reading of the brake fluid level make sure the top of the handlebar brake fluid reservoir is horizontal Brake fluid may corrode painted surfaces or plastic parts Always clean up any spilt fluid immediately SUse only the designated brake fluid Other fluids may deteriorate the rubber seals causing leakage and poor brake perfor mance SRefill with the same type of fluid Mix...

Page 66: ...Replace the brake shoes as a set Refer to REAR WHEEL in CHAPTER 6 EB304050 BRAKE LIGHT SWITCH ADJUSTMENT The brake light switch is operated by move ment of the brake pedal Adjustment is correct when the brake light comes on just before the braking effect actual ly starts 1 Check Brake light operation timing Incorrect Adjust 2 Adjust Brake light operating timing Adjustment steps Hold the main body ...

Page 67: ...onnect a clear plastic hose 1 tightly to the caliper bleed screw 2 d Place the other end of the hose into a con tainer e Slowly apply the brake lever several times f Pull the lever in Hold the lever in position g Loosen the bleed screw and allow the lever to travel towards its limit h Tighten the bleed screw when the lever limit has been reached then release the lever i Repeat steps e to h until a...

Page 68: ...AKE FLUID LEVEL INSPEC TION Check brake operation after bleeding the brake system SR304093 DRIVE CHAIN SLACK ADJUSTMENT Before checking and adjusting rotate the rear wheel several revolutions and check the slack at several points to find the tightest point Check and if necessary adjust the drive chain slack with the rear wheel in this tightest position Too little chain slack will overload the en g...

Page 69: ...pecified drive chain slack is obtained Clockwise Chain slack is decreased Counter clockwise Chain slack is increased Turn each chain adjuster exactly the same amount to maintain correct axle alignment There are marks e on each chain adjuster Use them when adjusting the slack for proper alignment SBefore tightening the axle nut to specification make sure that there is no clearance at the ad juster ...

Page 70: ...y bearings Grasp the bottom of the lower front fork tubes and gently rock the fork assembly Looseness Adjust the steering head 4 Adjust Steering head Adjustment steps Tighten the ring nut 1 using the ring nut wrench 2 Loosen the ring nut completely then tighten it When tighten the ring nut should be steady the ball bearings and steering shaft moving smoothly Ring nut wrench 90890 01403 Steering ri...

Page 71: ...e 3 Check SOperation Push down hard on the handlebars several times Unsmooth operation Repair Refer to FRONT FORK in CHAPTER 6 YP304160 REAR SHOCK ABSORBER ADJUSTMENT SAlways adjust each rear shock absorber preload to the same setting Uneven ad justment can cause poor handling and loss of stability SSecurely support the scooter so there is no danger of it falling over 1 Adjust SSpring preload Turn...

Page 72: ...ressure and suspen sion must be adjusted according to the total weight of the cargo rider passenger and accessories fairing saddlebags etc if approved for this model and according to whether the motorcycle will be operated at high speed or not NEVER OVERLOAD THE MOTORCYCLE SOperation of an overloaded motorcycle could cause tire damage accident or inju ry Basic weight With oil and full fuel tank 11...

Page 73: ...l Tube type tire only T beless type wheel Tube type or Tubeless type wheel yp tubeless tire Be sure to install the correct tube when us ing tube type tires After extensive tests the tires listed below have been approved by Yamaha Motor Co Ltd for this model No guarantee concern ing handling characteristics can be given if a tire combination other than one ap proved by Yamaha is used on this motor ...

Page 74: ...Spokes 1 Bending damage Replace Loose spoke Retighten 2 Tighten SSpokes Be sure to tighten the spokes before and after break in Nipple 2 Nm 0 2 mSkg EB304180 WHEEL INSPECTION 1 Inspect SWheels Damage Bends Replace Always balance the wheel when a tire or wheel has been changed or replaced Never attempt to make any repairs to the wheel ...

Page 75: ...als Dirt Clean with a wire brush Poor connection Correct After cleaning the terminals apply a light coat of grease to the terminals 4 Inspect SBreather hose Obstruction Remove Damage Replace When inspecting the battery make sure that the breather hose is routed correctly If the breather hose is positioned in such a way as to allow battery electrolyte or gas to come into contact with the frame this...

Page 76: ...d highly caustic Always follow these preventive measures SAvoid bodily contact with electrolyte as it can cause severe burns and permanent eye injury SWear protective eye gear when handling or working near batteries Antidote EXTERNAL SSKIN Flush with water SEYES Flush with water for 15 minutes and get immediate medical attention Antidote INTERNAL SDrink large quantities of water or milk fol lowed ...

Page 77: ...covers left and right Refer to SIDE COVER SEAT AND FUEL TANK section T305010 FUSE INSPECTION Always turn off the main switch when checking or replacing the fuse Otherwise a short circuit may occur 1 Remove Side covers left and right Refer to SIDE COVER SEAT AND FUEL TANK section Fuse holder 1 2 Inspect Fuse Inspection steps Connect the pocket tester to the fuse and check it for continuity Set the ...

Page 78: ...heck the electrical circuit Never use a fuse with a rating other than that specified Never use other materials in place of a fuse An improper fuse may cause ex tensive damage to the electrical system malfunction of lighting and ignition systems and could possibly cause a fire 4 Install SFuse holder SSide cover left and right Refer to SIDE COVER SEAT AND FUEL TANK section EB305022 HEADLIGHT BEAM AD...

Page 79: ...ALVE SPRINGS 4 14 VALVES AND VALVE SPRINGS REMOVAL 4 15 VALVES AND VALVE GUIDES 4 15 VALVE SEATS INSPECTION 4 17 VALVES AND VALVE SPRINGS INSTALLATION 4 18 CYLINDER AND PISTON 4 20 PISTON AND PISTON RINGS REMOVAL 4 21 CYLINDER AND PISTON INSPECTION 4 21 PISTON RING INSPECTION 4 23 PISTON PIN INSPECTION 4 24 PISTON RINGS PISTON AND CYLINDER INSTALLATION 4 24 CLUTCH 4 26 CRANKCASE COVER RIGHT 4 26 C...

Page 80: ... CLUTCH 4 46 CDI MAGNETO REMOVAL 4 47 STARTER CLUTCH INSPECTION 4 47 STARTER CLUTCH INSTALLATION 4 48 CDI MAGNETO INSTALLATION 4 48 CRANK CASE AND CRANKSHAFT 4 50 CRANKCASE 4 50 CRANKSHAFT AND BALANCER WEIGHT 4 52 CRANKCASE SEPARATION 4 53 PLUNGER SEAL REMOVAL 4 53 CRANKSHAFT INSPECTION 4 54 PLUNGER SEAL INSTALLATION 4 55 BALANCER WEIGHT INSTALLATION 4 55 CRANKCASE INSTALLATION 4 55 TRANSMISSION S...

Page 81: ...pipe Ass y Exhaust pipe gasket Ground lead Starting motor read CDI magneto read Plug cap 1 1 1 1 1 1 1 Refer to SIDE COVER SEAT AND FUEL TANK section in CHAPTER 3 Remove the parts in order Reverse the removal procedure for installation 12 Nm 1 2 m kg 20 Nm 2 0 m kg ENGINE REMOVAL ENG EB400000 ENGINE OVERHAUL ENGINE RE MOVAL EXHAUST PIPE STARTING MOTOR AND WIRE READ ...

Page 82: ...ift pedal Drive sprocket cover Rear wheel axle nut Sprocket holder Drive sprocket drive chain 1 1 1 1 1 1 1 1 Remove the parts in order Loosen the axle nut and slacken the drive chain NOTE Refer to CARBURETOR section in CHAPTER 5 Reverse the removal procedure for installation 10 Nm 1 0 m kg 65 Nm 6 5 m kg 8 Nm 0 8 m kg 7 Nm 0 7 m kg CARBURETOR CLUTCH CABLE AND DRIVE CHAIN ...

Page 83: ...gine stay Engine mount bolt rear upper Engine mount bolt rear under Engine 1 1 1 1 1 Remove the parts in order Securely support the motorcycle so there is no danger of it falling over Reverse the removal procedure for installation 33 Nm 3 3 m kg 33 Nm 3 3 m kg 33 Nm 3 3 m kg 33 Nm 3 3 m kg 33 Nm 3 3 m kg ENGINE ...

Page 84: ...ide O ring Carburetor joint O ring Timing mark cap O ring Center cap O ring 1 1 1 1 1 1 1 1 1 1 1 1 1 Remove the parts in order Refer to SIDE COVER SEAT AND FUEL TANK REMOVAL section in CHAPTER 3 Refer to ENGINE REMOVAL section in CHAPTER 4 Refer to CARBURETOR section in CHAPTER 5 Refer to ENGINE REMOVAL section in CHAPTER 4 Reverse the removal procedure for installation 10 Nm 1 0 m kg 2 Nm 0 2 m ...

Page 85: ...m sprocket Timing chain Ignition coil Cylinder head Dowel pins Gasket Cylinder head gasket 1 1 1 1 1 1 1 3 1 1 Remove the parts in order Refer to CYLINDER HEAD REMOVAL INSTALLATION section Refer to CYLINDER HEAD INSTALLATION section Reverse the removal procedure for installation 22 Nm 2 2 m kg 20 Nm 2 0 m kg 5 Nm 0 5 m kg 60 Nm 6 0 m kg 30 Nm 3 0 m kg CYLINDER HEAD ...

Page 86: ...aft counterclockwise with a wrench and align the I mark c with the cylinder head match mark d when the piston is at TDC on the compression stroke 2 Loosen Cam sprocket bolt 1 3 Remove Timing chain tensioner assembly 1 4 Remove Cam sprocket bolt Cam sprocket 1 Timing chain 2 Fasten a safety wire to the timing chain to prevent it from falling into the crankcase ...

Page 87: ...hreads Valve seats 2 Inspect Cylinder head Scratches damage Replace 3 Measure Cylinder head warpage Out of specification Resurface Cylinder head warpage Less than 0 03 mm Warpage measurement and resurfacement steps Place a straightedge and a feeler gauge across the cylinder head Measure the warpage If the warpage is out of specification resurface the cylinder head Place a 400 600 grit wet abrasive...

Page 88: ...rclockwise until the slit 1 matches the stationary pointer 2 Align the dowel pin 3 on the camshaft with the stationary pointer 4 on the cylinder head Align the I mark 5 on the cam sprocket with the stationary pointer 6 on the cylinder head Fit the timing chain 7 onto cam sprocket 8 and install the cam sprocket on the camshaft When installing the cam sprocket keep the tim ing chain as tight as poss...

Page 89: ...e magneto mounting bolt with a wrench 6 Check Magneto rotor slit Align the stationary pointer with the crank case cover left Cam sprocket I mark Align the stationary pointer with the cylinder head Out of alignment Adjust 7 Check Timing chain tension Refer to TIMING CHAIN ADJUSTMENT section in CHAPTER 3 Valve clearance Refer to VALVE CLEARANCE ADJUST MENT section in CHAPTER 3 ...

Page 90: ...r arm shaft exhaust side Rocker arm O ring Nut Adjuster 1 1 1 1 1 1 2 1 2 2 Remove the parts in order Refer to the CYLINDER HEAD section Refer to the ROCKER ARM AND ROCKER ARM SHAFT REMOVAL CAMSHAFT AND ROCKER ARM INSTALLATION section Refer to the CAMSHAFT AND ROCKER ARM INSTALLATION section Reverse the removal procedure for installation 14 Nm 1 4 m kg 14 Nm 1 4 m kg 8 Nm 0 8 m kg CAM SHAFT AND RO...

Page 91: ...haft and slide out the shaft Rocker arm shaft puller bolt 90890 01083 Weight 90890 01084 YP402052 CAMSHAFT INSPECTION 1 Inspect Cam lobes Pitting Scratches Blue discoloration Replace 2 Measure Cam lobes length A and B Out of specification Replace Cam lobes length Intake A 36 537 36 637 mm Limit 36 45 mm B 30 13 30 231 mm Limit 30 05 mm Exhaust A 36 577 36 677 mm Limit 36 49 mm B 30 214 30 314 mm L...

Page 92: ...ce Inspect the surface condition of the rocker arm shafts Pitting scratches blue discoloration Re place or check lubrication Measure the inside diameter a of the rocker arm holes Out of specification Replace Inside diameter rocker arm 12 000 12 018 mm Limit 12 036 mm Measure the outside diameter of the rocker arm shafts Out of specification Replace Outside diameter rocker arm shaft 11 985 11 991 m...

Page 93: ...bdenum disulfide oil onto the inside of the rocker arm Install the rocker arm shaft intake mach the cut away a and bolt hole b Make sure that the rocker shaft install direction Install the rocker arm shaft into the thread side for the out 4 Install Camshaft 1 Collar 2 Apply engine oil onto the cam profile face and journal face Install the camshaft mach the dowel pin a and cylinder head mark b 5 In...

Page 94: ... Valve intake Valve exhaust Valve guide stem seal Spring seat 4 2 2 2 1 1 2 2 Remove the parts in order Refer to CYLINDER HEAD section Refer to CAMSHAFT AND ROCKER ARMS section Refer to VALVES AND VALVE SPRINGS REMOVAL INSTALLATION section Refer to VALVES AND VALVE SPRINGS INSTALLATION section Reverse the removal procedure for installation VALVES AND VALVE SPRINGS ENG VALVES AND VALVE SPRINGS ...

Page 95: ... 90890 01253 Valve spring compressor attachment 90890 04108 NB402010 VALVES AND VALVE GUIDES 1 Measure Stem to guide clearance Stem to guide clearance valve guide inside diameter valve stem diameter Out of specification Replace the valve guide Clearance stem to guide Intake 0 010 0 037 mm Limit 0 08 mm Exhaust 0 025 0 052 mm Limit 0 10 mm 2 Replace Valve guide Replacement steps Heat the cylinder h...

Page 96: ...0890 04066 Reface the valve seat after replacing the valve guide 3 Eliminate Carbon deposits from the valve face 4 Inspect Valvel face Pitting wear Grind the face Valve stem end Mushroom shape or diameter larger than the body of the stem Replace 5 Measure Margin thickness a Out of specification Replace Margin thickness Intake 0 8 1 2 mm Exhaust 0 8 1 2 mm 6 Measure Runout valve stem Out of specifi...

Page 97: ... face Install the valve into the cylinder head Press the valve through the valve guide and onto the valve seat to make a clear pattern Measure the valve seat width Where the valve seat and valve face made contact blueing will have been removed If the valve seat is too wide too narrow or the seat is not centered the valve seat must be re placed EB402020 4 Lap Valve face Valve seat After replacing t...

Page 98: ...ck and forth be tween your hand Apply a fine lapping compound to the valve face and repeat the above steps Make sure to clean off all compound from the valve face and valve seat after every lapping operation Apply Mechanic s blueing dye Dykem b to the valve face Install the valve into the cylinder head Press the valve through the valve guide and onto the valve seat to make a clear pattern Measure ...

Page 99: ... Spring retainer 5 Install the valve spring with the larger pitch a facing upwards b Smaller pitch 4 Install Valve cotters 1 Install the valve cotters while compressing the valve spring with a valve spring compressor and attachment 2 Valve spring compressor 90890 01253 Valve spring compressor attachment 90890 04108 5 Secure the valve cotters onto the valve stem by tapping lightly with a piece of w...

Page 100: ...in Cylinder gasket Piston pin circlip Piston pin Piston Piston ring set 1 1 1 1 2 1 2 1 1 1 Remove the parts in order Refer to CYLINDER HEAD section Refer to PISTON AND PISTON RINGS REMOVAL section Refer to PISTON RINGS PISTON AND CYLINDER INSTALLATION section Refer to PISTON RINGS PISTON AND CYLINDER INSTALLATION section Reverse the removal procedure for installation CYLINDER AND PISTON ...

Page 101: ... ring Oil ring When removing the piston ring open the end gap of the ring by fingers and push up the other side of the ring EB402100 CYLINDER AND PISTON INSPECTION 1 Inspect Cylinder and piston walls Vertical scratches Rebore or replace the cylinder and the piston 2 Measure Piston to cylinder clearance Measurement steps 1st step Measure the cylinder bore C with a cylinder bore gauge Measure the cy...

Page 102: ... skirt diameter P with a micrometer a 5 5 mm from from the piston bottom edge Piston size P Standard 56 960 56 975 mm Oversize 1 0 25 mm Oversize 2 0 50 mm If out of specification replace the piston and the piston rings as a set 3rd step Calculate the piston to cylinder clearance us ing the following formula Piston to cylinder clearance Cylinder bore C Piston skirt diameter P Piston to cylinder cl...

Page 103: ...ring Limit 0 03 0 07 mm 0 15 mm 2nd ring Limit 0 02 0 06 mm 0 15 mm 2 Position Piston ring into the cylinder Push the ring with the piston crown so that the ring will be at a right angle to the cylinder bore a 5 mm 3 Measure End gap Out of specification Replace You cannot measure the end gap on the expan der spacer of the oil ring If the oil ring rails show excessive gap replace all three rings En...

Page 104: ...on inside diameter b Calculate the piston pin to piston clearance using the following formula Piston pin to piston clearance Bore size piston pin Outside diameter piston pin If out of specification replace the piston Clearance piston pin to piston 0 010 0 035 mm EB404184 PISTON RINGS PISTON AND CYLINDER INSTALLATION 1 Install Top ring 1 2nd ring 2 Side rails oil ring 3 Expander spacer oil ring 4 M...

Page 105: ...ling into the crank case Make sure to install each piston in its respec tive cylinder 3 Install Gasket cylinder Dowel pins 4 Position Piston rings Offset the piston ring end gaps as shown a Top ring end b Oil ring end lower c Oil ring end upper d 2nd ring end 5 Lubricate Piston outer surface Piston ring Cylinder inner surface 6 Install Gasket cylinder 1 Cylinder 2 Install the cylinder with one han...

Page 106: ...he engine oil Nut Foot rest right Clutch cable Crankcase cover right Crankcase cover gasket right Dowel pins 1 1 1 1 1 2 Remove the parts in order Refer to ENGINE OIL REPLACEMENT section in CHAPTER 3 Reverse the removal procedure for installation 45 Nm 4 5 m kg 7 Nm 0 7 m kg CLUTCH CRANKCASE COVER RIGHT ...

Page 107: ... to CLUTCH INSTALLATION section Clutch removal Sprocket cover Clutch springs Pressure plate Friction plates Clutch plates Nut Lock washer Clutch boss Plate washer Primary driven gear Ball Push rod 2 Push lever screw Gasket Refer to CLUTCH INSTALLATION section Refer to CLUTCH REMOVAL INSTALLATION section 8 Nm 0 8 m kg 70 Nm 7 0 m kg 12 Nm 1 2 m kg 6 Nm 0 6 m kg CLUTCH ...

Page 108: ...lever axle Torsion spring Circlip Oil seal Nut Washer Push rod 1 O ring Push plate 1 1 1 1 1 1 1 1 1 Refer to CLUTCH INSTALLATION sec tion Refer to CLUTCH INSTALLATION sec tion Reverse the removal procedure for installation 8 Nm 0 8 m kg 70 Nm 7 0 m kg 12 Nm 1 2 m kg 6 Nm 0 6 m kg ...

Page 109: ...ge wear Replace the friction plates as a set 2 Measure Friction plate thickness Out of specification Replace the friction plates as a set Measure at four places Thickness friction plate 2 9 3 1 mm Limit 2 7 mm 3 Inspect Clutch plates Damage Replace the clutch plates as a set 4 Measure Clutch plate warpage Out of specification Replace the clutch plates as a set Use a surface plate and a feeler gaug...

Page 110: ... place Clutch boss splines 2 Scoring wear damage Replace clutch boss Scoring on the clutch housing dogs and the clutch boss splines will cause erratic operation SR PUSH ROD INSPECTION 1 Inspect Push rod 1 1 Ball 2 Push rod 2 3 Wear crack damage Replace SR CLUTCH INSTALLATION 1 Install Push lever axle 1 Gasket 2 Screw 3 2 Install Primary driven gear 1 Plate washer 2 Clutch boss 3 Tighten the nut pr...

Page 111: ...ll Friction plate 1 Clutch plate 2 Install the clutch plates and friction plates al ternately on the clutch boss starting with a fric tion plate and ending with a friction plate Coat all clutch and friction plates with engine oil before installation 6 Install Push rod 2 Ball 7 Install Push rod 1 1 O ring 2 Push plate 3 Plate washer 4 Nut 5 push rod 1 8 Install Pressure plate 1 Compression springs ...

Page 112: ...sh lever assembly b Match mark on the crankcase 10 Adjust Push lever position Adjustment steps Loosen the locknut 1 Turn the adjuster 2 clockwise or counter clockwise to match alignment marks Hold the adjuster to prevent it from moving and tighten the locknut to specification Take care not to overtighten the adjuster 2 and to remove the free play between both push rods Tighten the lock nut 1 ...

Page 113: ...drive gear Oil pump cover Oil pump assembly Gasket oil pump cover 1 1 1 1 1 1 Remove the parts in order Refer to CLUTCH section Refer to PRIMARY DRIVE GEAR REMOVAL INSTALLATION section Refer to OIL PUMP REMOVAL INSTAL LATION section Reverse the removal procedure for installation 7 Nm 0 7 m kg 50 Nm 5 0 m kg OIL PUMP ...

Page 114: ...bly Oil pump housing Dowel pin Oil pump driven gear Dowel pins Inner rotor Outer rotor Housing 1 1 1 2 1 1 1 Disassemble the parts in order Reverse the disassembly procedure for assembly 7 Nm 0 7 m kg 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 3 4 5 6 7 ...

Page 115: ...the inner rotor 1 and the outer ro tor 2 Side clearance B between the outer rotor 2 and the pump housing 3 Out of specification Replace the oil pump assembly Housing and rotor clearance C between the pump housing 3 and the ro tors 1 2 Out of specification Replace the oil pump assembly Tip clearance A 0 03 0 09 mm Limit 0 14 mm Side clearance B 0 10 0 15 mm Limit 0 35 mm Housing and rotor clearance...

Page 116: ...p assembly Recommended lubricant Engine oil SR404140 PRIMARY DRIVE GEAR INSTALLATION 1 Install Primary drive gear 1 Lock washer 2 Nut primary drive gear 3 Place a folded aluminium plate or copper washer a between the teeth of the balancer drive gear 4 and balancer driven gear 5 Bend the lock washer tab after tighten the nut flats ...

Page 117: ...washer Balancer drive gear Buffer boss Compression spring Dowel pins Woodruff key Plate washer 1 1 1 1 1 1 1 6 3 1 1 Remove the parts in order Refer to CLUTCH section Refer to OIL PUMP section Refer to BALANCER DRIVEN GEAR REMOVAL BALANCER GEAR INSTALLATION section Reverse the removal procedure for installation Refer to BALANCER DRIVE GEAR ASSEMBLY section 50 Nm 5 0 m kg BALANCER GEAR ...

Page 118: ... of the balancer drive gear 4 and balancer driven gear 3 SR DRIVE GEAR INSPECTION 1 Inspect Balancer drive gear 1 Buffer boss 2 Compression spring 3 Dowel pins 4 Wear Pitting Scratches Replace SR BALANCER DRIVE GEAR ASSEMBLY 1 Assembly Dowel pins 1 Compression springs 2 Install the dowel pins and compression springs alternately as shown as 2 Install Buffer boss 1 Align the punched mark a on the bu...

Page 119: ...r driven gear then mesh the balancer driven gear match mark a and ba lancer drive gear assembly match mark b 2 Install Lock washer 1 Nut balancer drive gear 2 Place a folded aluminium plate or copper washer a between the teeth of the balancer drive gear 3 and balancer driven gear 4 Bend the lock washer tab after tighten the nut flats ...

Page 120: ...l Clutch Shift pedal Shift shaft Plate washer Torsion spring Stopper lever Plate washer Circlip Torsion spring Collar Tension spring 1 1 1 1 1 1 1 1 1 Remove the parts in order Refer to CLUTCH section Refer to ENGINE REMOVAL section Refer to SHIFT SHAFT REMOVAL INSTALLATION section 12 Nm 1 2 m kg SHIFT SHAFT AND SEGMENT ...

Page 121: ...ENT ENG Order Job name Part name Q ty Remarks 10 11 12 13 Screw Segment Dowel pins short length Dowel pins long length 1 1 4 1 Reverse the removal procedure for installation Refer to SEGMENT INSTALLATION section 12 Nm 1 2 m kg ...

Page 122: ...FT SHAFT INSPECTION 1 Inspect Stopper lever Roller turns roughly Replace Bends damage Replace 2 Inspect Torsion springs stopper lever and shift arm Wear damage Replace 3 Inspect Shift shaft assembly 1 Shift lever 2 Bends wear damage Replace SR SEGMENT INSTALLATION 1 Install Segment 1 Dowel pins 2 short length Dowel pin 3 long length Install the dowel pin 2 long length into the hole beside the matc...

Page 123: ...TALLATION 1 Install Shift shaft assembly Instaling steps Set the stopper lever and return spring to the shift shaft Mesh the stopper lever 1 with the shift cam segment Install the shift lever 2 to the shift cam seg ment After installing the shift shaft check the shift cam for smooth operation by turning the shift shaft with your hand 2 Check Shift lever 1 position Gaps a and b are not equal Replac...

Page 124: ...eto lead couplers Neutral switch lead connector Crankcase cover left Gasket Dowel pins 1 1 1 2 Remove the parts in order Refer to ENGINE OIL REPLACEMENT section in CHAPTER 3 Refer to SIDE COVER SEAT AND FUEL TANK section in CHAPTER 3 Refer to ENGINE REMOVAL section Reverse the removal procedure for installation 7 Nm 0 7 m kg CDI MAGNETO AND STARTER CLUTCH CRANKCASE COVER LEFT ...

Page 125: ...t name Q ty Remarks 1 2 3 4 Pickup coil and stator coil removal Clamp stator coil Clamp pickup coil Pickup coil Stator coil 1 1 1 1 Remove the parts in order Reverse the removal procedure for installation 3 Nm 0 3 m kg 7 Nm 0 7 m kg PICKUP COIL AND STATOR COIL ...

Page 126: ...key Starter wheel gear Shim Dowel pins Inner Spring caps Compression springs Dowel pins outer Starter clutch 1 1 1 1 1 1 3 3 3 3 1 Remove the parts in order Refer to CDI MAGNETO REMOVAL INSTALLATION section Refer to CDI MAGNETO INSTALLATION section Refer to STARTER CLUTCH INSTALLATION seciton Remove the removal procedure tor installation 30 Nm 3 0 m kg 50 Nm 5 0 m kg CDI MAGNETO AND STARTER CLUTCH...

Page 127: ...tachment 4 Rotor puller 90890 01080 Rotor puller attachment 90890 04052 SR402163 STARTER CLUTCH INSPECTION 1 Check Starter clutch operation Push the dowel pins to the arrow direction Unsmooth operation Replace Checking steps Hold the starter clutch When turning the starter wheel gear clockwise a the starter clutch and the starter wheel gear should be engaged If not the starter clutch is faulty Rep...

Page 128: ...embly by us ing the center punch 3 Install Compression springs 1 Spring caps 2 Dowel pins 3 YP404131 C D I MAGNETO INSTALLATION 1 Install Shim 1 Starter wheel gear 2 Woodruff key 3 2 Install C D I magneto assembly 1 Clean the tapered portion of the crankshaft and the magneto hub When installing the magneto rotor make sure the woodruff key is properly seated in the key way of the crankshaft and tur...

Page 129: ...4 49 CDI MAGNETO AND STARTER CLUTCH ENG 50 Nm 5 0 m kg NOTE 3 Tighten CDI magneto assembly 1 Tighten the bolt while holding the CDI magneto assembly with the sheave holder 2 Sheave holder 90890 01701 ...

Page 130: ...t CDI magneto starter clutch Timing chain guide intake 1 Remove the parts in order Refer to ENGINE REMOVAL section Refer to CYLINDER HEAD section Refer to CYLINDER AND PISTON section Refer to CLUTCH section Refer to OIL PUMP section Refer to BALANCER DRIVE GEAR section Refer to SHIFT SHAFT AND SEGMENT section Refer to CDI MAGNETO AND STARTER CLUTCH section 8 Nm 0 8 m kg 7 Nm 0 7 m kg CRANK CASE AN...

Page 131: ...ANK SHAFT ENG Order Job name Part name Q ty Remarks 2 3 4 Timing chain Crankcase Dowel pins 1 1 2 Refer to CRANKCASE SEPARATION INSTALLATION section Reverse the removal procedure for installation 8 Nm 0 8 m kg 7 Nm 0 7 m kg ...

Page 132: ...r weight Crankshaft assembly Dowel pin Plunger seal Compression spring Bearing balancer weight Bearing crankshaft right 1 1 1 1 1 1 1 Remove the parts in order Refer to BALANCER WEIGHT INSTALLATION seciton Refer to PLUNGER SEAL REMOVAL INSTALLATION section Reverse the removal procedure for installation CRANKSHAFT AND BALANCER WEIGHT ...

Page 133: ... crankcase half Set the left crankcase half under then put in the flat head screw driver to the separating slit a Do not use the flat head screw driver ex cept place as shown The left crankcase half should be under Separate the crankcase after first checking that the shift cam segments and the drive axle circlip can be removed Do not damage the crankcase mating sur faces SR PLUNGER SEAL REMOVAL 1 ...

Page 134: ...m 2 Measure Big end side clearance Out of specification Replace big end bear ing crank pin and or connecting rod Big end side clearance 0 35 0 65 mm Limit 0 1 mm 3 Measure Crank width Out of specification Replace crankshaft Crank width 55 95 56 00 mm 4 Inspect Timing chain sprocket 1 Wear Damage Replace crankshaft Bearing 2 Wear Crack Damage Replace crank shaft 5 Inspect Crankshaft journal Clogged...

Page 135: ...eight assembly 2 Do not use the hammer forcefully during installation of the crankshaft Damage the crankcase oil seal lip and gear teeth SR404073 CRANKCASE INSTALLATION 1 Clean all the gasket mating surface and crankcase mating surface thoroughly 2 Apply Sealant onto the crankcase mating surfaces Yamaha bond No 1215 90890 85505 DO NOT ALLOW any sealant to come in con tact with the oil gallery a 3 ...

Page 136: ... cam Shift fork 1 C center Shift fork 2 R right Shift fork 3 L left Main axle assembly Plate washer Drive axle assembly Plate washer 1 1 1 1 1 1 1 1 1 1 Remove the parts in order Refer to CRANKCASE AND CRANKSHAFT section Refer to TRANSMISSION SHIFT CAM AND SHIFT FORK INSTALLATION section Reverse the removal procedure for installation Refer to TRANSMISSION SHIFT CAM AND SHIFT FORK REMOVAL INSTALLAT...

Page 137: ...el gear Fifth wheel gear Circlip washer Third wheel gear Forth wheel gear Drive axle Second pinion gear Forth pinion gear Third pinion gear Circlip washer Fifth pinion gear gear Main axle 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Disassemble the parts in order Reverse the disassembly procedure for assembly 8 1 2 3 4 5 6 7 9 10 11 12 13 DRIVE AXLE AND MAIN AXLE ...

Page 138: ...402190 SHIFT FORK SHIFT CAM INSPECTION 1 Inspect Shift fork cam follower 1 Shift fork pawl 2 Scoring bends wear damage Replace 2 Inspect Shift cam grooves Wear damage scratches Replace Shift cam segment Damage wear Replace 3 Inspect Shift fork 1 C center 1 Shift fork 2 R right 2 Shift fork 3 L left 3 Guide bar 4 Shift cam 5 Dowel pin 6 Roll the guide bar on a flat surface Bends Replace Do not atte...

Page 139: ... 91 1 mm 2 Install O ring 1 To the drive sprocket folder groove 3 Install Shift fork 3 L left 1 face the L side for the clutch side Shift fork 2 R right 2 face the R side for the clutch side Shift fork 1 C center 3 face the C side for the magneto side Shift fork guide bar 1 4 long Shift fork guide bar 2 5 short Install the shift forks with the embossed mark to the right and in sequence R C L begin...

Page 140: ...ENG ...

Page 141: ...CHAPTER 5 CARBURETION CARBURETOR 5 1 CARBURETOR ASSEMBLY 5 4 FUEL LEVEL ADJUSTMENT 5 5 ...

Page 142: ......

Page 143: ...lead Carburetor joint clamp screw Air filter joint clamp screw Carburetor assembly Carburetor top 1 1 1 1 Remove the parts in order NOTE Refer to SIDE COVER SEAT AND FUEL TANK section in CHAPTER 3 Disconnect the cable from wireharness Loosen Reverse the removal procedure for installation NOTE EB600000 CARBURETION CARBURETOR ...

Page 144: ... valve assembly Throttle valve spring Mixing chamber top O ring Drain screw assembly Float chamber Gasket float chamber Float pin float Needle valve assembly Main jet Main nozzle O ring 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Disassemble the parts in order Refer to CARBURETOR ASSEMBLY section 1 10 2 3 4 5 6 7 8 9 11 ...

Page 145: ...Q ty Remarks Pilot screw assembly Pilot jet Throttle stop screw assembly Starter plunger assembly Screw gasket Heater unit washer 1 1 1 1 1 1 1 1 Reverse the disassembly procedure for assembly Refer to CARBURETOR ASSEMBLY section 12 13 14 15 16 17 ...

Page 146: ...ning Before assembling wash all parts in clean petroleum based solvent Always use a new gasket 1 Install Pilot jet 1 Pilot screw assembly 2 Pilot screw turn out 2 turns out 2 Install O ring Main nozzle 1 Main jet 2 3 Install Valve seat 1 Needle valve 2 4 Install Float 1 Float pin 2 ...

Page 147: ...e positioned vertically Connect the fuel level gauge 1 to the drain pipe 2 Fuel level gauge 90890 01312 Loosen the drain screw 3 Hold the gauge vertically next to the float chamber line Measure the fuel level a with the gauge If the fuel level is incorrect adjust the fuel level Remove the carburetor Inspect the valve seat and needle valve If either is worn replace them both If both are fine adjust...

Page 148: ...CARB ...

Page 149: ...PECTION 6 17 BRAKE CALIPER ASSEMBLY 6 17 CALIPER INSTALLATION 6 18 REAR WHEEL REAR BRAKE AND DRIVE CHAIN 6 20 REAR WHEEL AND REAR BRAKE 6 20 DRIVE CHAIN 6 24 REAR WHEEL DISASSEMBLY 6 25 REAR WHEEL INSPECTION 6 25 REAR BRAKE INSPECTION 6 25 DRIVE CHAIN INSPECTION 6 26 BRAKE SHOE PLATE ASSEMBLY 6 27 REAR WHEEL ASSEMBLY 6 28 DRIVE CHAIN INSTALLATION 6 28 FRONT FORK 6 29 FRONT FORK DISASSEMBLY 6 31 FR...

Page 150: ...STEERING INSTALLATION 6 42 REAR SHOCK ABSORBER AND SWINGARM 6 43 SWINGARM INSPECTION 6 44 ...

Page 151: ...er gear unit assembly Brake disc 1 1 1 1 1 1 1 Remove the parts in order Loosen the axle pinch bolt NOTE 59 Nm 5 9 m kg 20 Nm 2 0 m kg 23 Nm 2 3 m kg Securely support the motorcycle so there is no danger of it falling over Refer to FRONT WHEEL INSTALLATION section Refer to FRONT WHEEL ASSEMBLY section Reverse the removal procedure for installation WARNING EB700000 CHASSIS FRONT WHEEL AND BRAKE DIS...

Page 152: ...eal Bearing Spacer Spacer flange Bearing Order Job name Part name Q ty Remarks 1 1 1 1 1 Disassemble the parts in order Refer to FRONT WHEEL ASSEMBLY section Refer to FRONT WHEEL DISASSEMBLY ASSEMBLY section Reverse the disassembly procedure for reassembly 1 2 3 4 5 ...

Page 153: ...y rolling it on a flat surface Bends Replace Do not attempt to straighten a bent axle Wheel axle bending limit 0 25 mm 2 Inspect Front tire Wear damage Replace Refer to TIRE INSPECTION in CHAPTER 3 Front wheel Refer to WHEEL INSPECTION in CHAP TER 3 3 Check Spokes Bends damage Replace Loose spokes Retighten Turn the wheel and tap the spokes with a screwdriver A tight spoke will emit a clear ringin...

Page 154: ... set YP BRAKE DISC INSPECTION 1 Measure Brake disc deflection Maximum deflection 0 15 mm Out of specification Replace 2 Measure Brake disc thickness Brake disc thickness 4 0 mm Minimum thickness 3 5 mm Out of specification Replace YP FRONT WHEEL ASSEMBLY 1 Install Bearing 1 Spacer 2 Spacer flange 3 Bearing 4 Oil seal 5 Apply the lithium soap base grease on the bearing and oil seal lip when install...

Page 155: ...STALLATION Reverse the REMOVAL procedure Note the following points 1 Lubricate Front wheel axle Bearings Oil seal lips Drive driven gear speedometer Recommended lubricant Lithium soap base grease 2 Install Speedometer gear unit 1 Make sure that the wheel hub and the speedometer gear unit are installed with the two projections a meshed into the two slots b 3 Install Front wheel Make sure that the s...

Page 156: ... and or rim the wheel static balance should be adjusted Adjust the front wheel static balance with the brake disc installed 1 Remove Balancing weight 1 2 Set Wheel on a suitable stand 3 Find Heavy spot Procedure a Spin the wheel and wait for it to rest b Put an X1 mark on the wheel s bottom spot c Turn the wheel so that the X1 mark is 90_ up d Release the wheel and wait for it to rest Put an X2 ma...

Page 157: ...tart with the smallest weight Turn the wheel so that the heavy spot is 90_ up Check that the heavy spot is at rest there If not try another weight until the wheel is bal anced 5 Check Wheel static balance Checking steps Turn the wheel so that it comes to each point as shown Check that the wheel is at rest at each point If not readjust the front wheel static balance ...

Page 158: ...ame Q ty Remarks 1 2 3 Brake pad removal Bolt caliper support bolt Brake pads Pad support 1 2 1 Remove the parts in order Refer to BRAKE PAD REPLACEMENT section Reverse the removal procedure for installation 23 Nm 2 3 m kg FRONT BRAKE BRAKE PAD ...

Page 159: ...ads as a set if either is found to be worn to the wear limit 3 Push the caliper piston into the brake caliper by finger When pushing the caliper piston into the brake caliper brake fluid level in reservoir tank is increasing higher 4 Install Brake pad 1 Install the brake pad and move the brake caliper to the allow mark direction 5 Install Bolt caliper support bolt 6 Inspect Brake fluid level Refer...

Page 160: ...ew mirror right Brake lever compression spring Brake switch Union bolt Plate washer Brake hose Bracket master cylinder Master cylinder 1 1 1 1 1 2 1 1 1 Remove the parts in order Refer to MASTER CYLINDER INSTALLATION section Reverse the removal procedure for installation 2 Nm 0 2 m kg 9 Nm 0 9 m kg 30 Nm 3 0 m kg MASTER CYLINDER ...

Page 161: ...er disassembly Rubber boots Circlip Master cylinder kit Spring Order Job name Part name Q ty Remarks 1 1 1 Disassemble the parts in order Refer to MASTER CYLINDER ASSEMBLY section Reverse the disassembly procedure for reassembly 1 2 3 4 ...

Page 162: ...ce the master cylinder assembly 3 Inspect Diaphragm Wear damage Replace YP MASTER CYLINDER ASSEMBLY All internal brake components should be cleaned and lubricated with new brake fluid only before installation Recommended brake fluid DOT 4 or DOT 3 Replace the piston seals and dust seals whenever a master cylinder is disas sembled 1 Install Spring 1 Install the spring with its smaller diameter to t...

Page 163: ...R INSTALLATION 1 Install Master cylinder 1 Master cylinder bracket 2 Install the master cylinder bracket 2 with the UP mark facing upward 2 Install Plain washer 1 Brake hose 2 Plain washer 3 Union bolt 4 Install the brake hose as shown 3 Fill Reservoir tank Recommended brake fluid DOT 4 or DOT 3 Brake fluid may damage painted surfaces or plastic parts Always clean up spilled brake fluid immediatel...

Page 164: ...ing fluids may result in a harmful chemical reaction and lead to poor performance Be careful that water does not enter the sig nificantly lower the boiling point of the fluid may result in vapor lock 4 Air bleed Brake system Refer to AIR BLEEDING section in CHAP TER 3 5 Inspect Brake fluid level Brake fluid level is under the LOWER level line Fill up Refer to BRAKE FLUID INSPECTION section in CHAP...

Page 165: ... Drain teh brake fluid Brake hose holder Union bolt Plain washer Brake hose Caliper support bolt Caliper assembly 1 1 1 1 1 1 Remove the parts in order Refer to CALIPER INSTALLATION section 23 Nm 2 3 m kg 30 Nm 3 0 m kg 40 Nm 4 0 m kg Reverse the removal procedure for installation CALIPER ...

Page 166: ...per disassembly Brake pad Caliper piston Dust seal Piston seal Bleed screw Cap 2 2 2 1 Disassemble the parts i order Refer to BRAKE PAD section Refer to BRAKE CALIPER DISASSEMBLY ASSEMBLY section Reverse the disassembly procedure for reassembly 6 Nm 0 6 m kg 1 2 3 4 ...

Page 167: ... compressed air into the hose joint opening a Remove the caliper piston seals and reinstall the bigger side caliper pistons Repeat the previous steps to force out the smaller side caliper pistons from the brake cal iper body Never try to pry out the caliper piston YP CALIPER INSPECTION 1 Inspect Caliper cylinder 1 Caliper piston 2 Scratches wear Replace caliper assem bly EB702050 BRAKE CALIPER ASS...

Page 168: ...id to the outer surface and install YP CALIPER INSTALLATION 1 Install Caliper 1 Caliper support bolt 2 Brake hose 3 Plain washer 4 Union bolt 5 When installing the brake hose to the cali per lightly touch the brake hose with the stopper a on the caliper 2 Fill Reservoir tank Recommended brake fluid DOT 4 or DOT 3 Brake fluid may damage painted surfaces or plastic parts Always clean up spilled brak...

Page 169: ...harmful chemical reaction and lead to poor brake performance Be careful that water does not enter the master cylinder when refilling Water will significantly lower the boiling point of the brake fluid and may result in vapor lock 3 Air bleed Brake system Refer to AIR BLEEDING HYDRAULIC BRAKE SYSTEM in CHAPTER 3 4 Inspect Brake fluid level Brake fluid level is under the LOWER level line Fill up Ref...

Page 170: ...rear brake removal Adjuster Brake rod Pin Compression spring Cotter pin Tension bar Chain case Axle nut Chain puller Wheel axle Collar 1 1 1 1 1 1 1 1 2 1 1 Remove the parts in order Bend the end after installing NOTE 40 Nm 4 0 m kg 65 Nm 6 5 m kg 20 Nm 2 0 m kg REAR WHEEL REAR BRAKE AND DRIVE CHAIN REAR WHEEL AND REAR BRAKE ...

Page 171: ...name Q ty Remarks 12 13 14 15 16 17 18 Rear wheel assembly Collar Shoe plate Nut driven sprocket Circlip Washer Driven sprocket 1 1 1 4 1 1 1 Reverse the removal procedure for installation Refer to REAR WHEEL ASSEMBLY section 65 Nm 6 5 m kg 20 Nm 2 0 m kg 40 Nm 4 0 m kg ...

Page 172: ... Order Job name Part name Q ty Remarks Rear wheel disassembly Bearing Collar Spacer Oil seal Bearing 1 1 1 1 1 Disassemble the parts in order Refer to REAR WHEEL DISASSEMBLY ASSEMBLY section Reverse the disassembly procedure for reassembly 1 2 3 4 5 ...

Page 173: ...name Q ty Remarks Brake shoe plate disassembly Brake shoe kit Tension springs Cam lever Indicator plate Camshaft 2 2 1 1 1 Disassemble the parts in order Refer to BRAKE SHOE PLATE ASSEMBLY section Reverse the disassembly procedure for reassembly 1 2 3 4 5 9 Nm 0 9 m kg ...

Page 174: ...rocket holder Clip Plate Chain joint Drive chain Drive sprocket 1 1 1 1 1 1 1 1 1 Remove the parts in order Refer to REAR WHEEL REAR BRAKE AND DRIVE CHAIN section NOTE Refer to DRIVE CHAIN INSTALLATION section Loosen the axle nut and slacken the drive chain Reverse the removal procedure for installation 7 Nm 0 7 m kg 10 Nm 1 0 m kg 65 Nm 6 5 m kg 8 Nm 0 8 m kg DRIVE CHAIN ...

Page 175: ... Wear damage Replace SR701021 REAR BRAKE INSPECTION 1 Inspect Brake lining surface Wear damage Replace 2 Measure Brake lining thickness a Out of specification Replace Brake lining thickness Standard 4 mm Limit 2 mm When inspecting the brake lining do not spill oil or grease on the brake lining 3 Inspect Brake drum inner surface Oil Scratches Wear damage Replace 4 Measure Brake drum inside diameter...

Page 176: ...n sprocket 2 More than 1 2 tooth a wear Replace the drive chain Use new driven sprocket 3 Measure 10 link length a drive chain Out of specification Replace the drive chain 10 link length limit 122 mm Tighten the drive chain with a finger before measuring 10 link length is the distance between the inside edge of roller 1 and 11 as shown 10 link length measurement should be done at two or three diff...

Page 177: ...gn the projection a on the indicator plate with the camshaft notch b and install Check the proper position of the brake shoe 2 Install Cam lever 1 Align the punch mark c on the cam shaft with the mark made on the cam lever d Apply lithium soap base grease onto the brake cam shaft and pin 3 Install Brake shoes 1 Tension springs 2 When installing the springs and brake shoes take care not to damage t...

Page 178: ...tches the outside diame ter of the race of the bearing Always use a new oil seal Install the oil seal with its manufacturer s marks or numbers facing outward Do not strike the inner race of balls of the bearing Contact should be made only with the outer race 2 Install Driven sprocket 1 Washer 2 Circlip 3 Nut 4 T DRIVE CHAIN INSTALLATION 1 Install Drive chain 1 Chain joint 2 Plate 3 2 Install Clip ...

Page 179: ...er Cover Bolt washer Bolt under bracket Front fork assembly left Front fork assembly right 1 1 1 1 1 1 1 1 1 Remove the parts in order Refer to FRONT WHEEL AND BRAKE DISC section Loosen the bolt NOTE Refer to FRONT FORK INSTALLATION section Reverse the removal procedure for installation 48 Nm 4 8 m kg 30 Nm 3 0 m kg 40 Nm 4 0 m kg FRONT FORK ...

Page 180: ...aining clip Washer oil seal Inner tube assembly Oil seal Piston metal Damper rod Outer tube 1 1 1 1 1 1 1 1 1 1 1 1 1 Drain the fork oil NOTE Refer to FRONT FORK DISASSEMBLY ASSEMBLY section Refer to FRONT FORK ASSEMBLY section Disassemble the parts in order Reverse the disassembly procedure for assembly 1 2 3 4 5 6 7 8 9 11 65 Nm 86 5 m kg ...

Page 181: ...ld the fork leg horizontally Securely clamp the outer tube in a vise with soft jaws Separate the inner tube from the outer tube by pulling forcefully but carefully the inner tube Excessive force will damage the oil seal and or the metal damaged oil seal and met al must be replaced YP703030 FRONT FORK INSPECTION 1 Inspect Inner tube bending Inner tube bending limit 0 2 mm Scratches bends damage Rep...

Page 182: ...ensitive to foreign material When disassembling and assembling the front fork do not allow any foreign material to enter the oil SR FRONT FORK ASSEMBLY Reverse the DISASSEMBLY procedure Note the following points When assembling the front fork be sure to re place the following parts Piston metal Slide metal Oil seal Dust seal Before assembling the fork make sure that all of the components are clean...

Page 183: ...seal numbered side faces upward Fork seal driver weight 90890 01400 Attachment 90890 01367 3 Install Washer oil seal 1 Retaining clip 2 Dust seal 3 Adjust the retaining clip so that it fits into the out er tube groove 4 Inspect Inner tube operation Unsmooth operation Disassembly and re check 5 Fill Fork oil 1 Oil quantity 0 177 L Recommended oil Fork oil 15WT or equivalent 6 After filling up slowl...

Page 184: ...spring with its smaller pitch up ward Before installing the cap bolt apply grease to the O ring Temporarily tighten the cap bolt 9 Install Plate washer Spacer O ring Cap bolt EB70307250 FRONT FORK INSTALLATION Reverse the REMOVAL procedure Note the following points 1 Install Front fork 1 Plate washer 2 Temporary tighten the pinch bolts Pull up the inner tube until its end flushes the top of the un...

Page 185: ... front brake switch lead and clutch switch lead Master cylinder bracket Master cylinder Housing throttle grip Throttle cable Throttle grip assembly Handle bar switch right Clutch switch Clutch cable 1 1 1 1 1 1 1 1 1 1 Remove the parts in order Disconnect the connector NOTE Refer to HANDLEBAR INSTALLATION section 9 Nm 0 9 m kg 20 Nm 2 0 m kg HANDLEBAR ...

Page 186: ...marks 11 12 13 14 15 Handlebar switch left Grip left Lever holder left Upper holder Handlebar 1 1 1 2 1 Refer to HANDLEBAR REMOVAL section Refer to HANDLEBAR INSTALLATION section Reverse the removal procedure for installation 9 Nm 0 9 m kg 20 Nm 2 0 m kg ...

Page 187: ...nt handle bar as this may dangerously weaken the handlebar SR HANDLEBAR INSTALLATION 1 Install Handlebar 1 Upper handlebar holder 2 Apply a light coat of lithium soap base grease onto the handlebar right end The upper handlebar holders should be installed with the longer side a to the forward then tighten the front bolt as shown 2 Install Handlebar switch right 1 Grip assembly Throttle cable Cover...

Page 188: ...tall Master cylinder 1 Master cylinder bracket 2 Install the master cylinder bracket with the UP mark facing upward 4 Adjust Throttle cable free play Brake operation Refer to THROTTLE CABLE ADJUST MENT BRAKE LEVER ADJUSTMENT section in CHAPTER 3 ...

Page 189: ...ght Cover Meter cable Meter lead Meter assembly Handlebar crown Horn Ring nut Ball race cover Under bracket 1 1 1 1 1 1 1 1 1 1 1 Remove the parts in order Refer to FRONT FORK section Refer to HANDLEBAR section Disconnect the connector NOTE Refer to STEERING REMOVAL INSTALLATION section 40 Nm 4 0 m kg 1st step 38 Nm 3 8 m kg 2nd step 7 Nm 0 7 m kg STEERING UNDER BRACKET ...

Page 190: ... Remarks 10 11 12 13 14 Ball race upper Ball Ball Ball race center Ball race lower 1 22 19 1 1 Reverse the removal procedure for installation Refer to STEERING REMOVAL INSTALLATION section 40 Nm 4 0 m kg 1st step 38 Nm 3 8 m kg 2nd step 7 Nm 0 7 m kg ...

Page 191: ...r of it falling down STEERING INSPECTION 1 Wash the bearing and ball races with a sol vent 2 Inspect Bearings Ball races Pitting Damage Replace Bearing race replacement steps Remove the ball races on the head pipe using long rod 1 and the hammer as shown Remove the ball race on the under bracket us ing the floor chisel 2 and the hammer as shown Install the new dust seat and races Always replace be...

Page 192: ...EERING INSTALLATION Reverse the REMOVAL procedure Note the following points 1 Lubricate Bearings upper and lower Ball races Recommended lubricant Lithium soap base grease 2 Install Ring nut 1 Refer to STEERING HEAD INSPECTION section in CHAPTER 3 ...

Page 193: ... chain Rear shock absorber Nut Footrest assembly right Pivot shaft Footrest assembly left Swingarm Tension bar Cover swingarm Bush 2 1 1 1 1 1 1 1 2 Remove the parts in order Refer to REAR WHEEL REAR BRAKE AND DRIVE CHAIN section Reverse the removal procedure for installation 40 Nm 4 0 m kg 45 Nm 4 5 m kg 20 Nm 2 0 m kg 30 Nm 3 0 m kg REAR SHOCK ABSORBER AND SWINGARM ...

Page 194: ...AND SWINGARM CHAS T SWINGARM INSPECTION 1 Inspect Swingarm side play Free play exists Check side clearance Swingarm up and down movement Unsmooth movement bending rough spots Grease or replace bearings solid bushes and collars ...

Page 195: ...IT DIAGRAM 7 4 TROUBLESHOOTING 7 5 ELECTRIC STARTING SYSTEM 7 10 CIRCUIT DIAGRAM 7 10 STARTING CIRCUIT OPERATION 7 11 TROUBLESHOOTING 7 12 STARTER MOTOR 7 16 CHARGING SYSTEM 7 19 CIRCUIT DIAGRAM 7 19 TROUBLESHOOTING 7 20 LIGHTING SYSTEM 7 23 CIRCUIT DIAGRAM 7 23 TROUBLESHOOTING 7 24 LIGHTING SYSTEM CHECK 7 25 SIGNAL SYSTEM 7 28 CIRCUIT DIAGRAM 7 28 TROUBLESHOOTING 7 29 SIGNAL SYSTEM CHECK 7 31 ...

Page 196: ......

Page 197: ...y 9 Thermo switch 10 Sidestand switch 11 Rear brake switch 12 Neutral switch 13 Spark plug cap 14 Ignition coil 1 Horn 2 Flasher relay 3 Main switch 4 Starter relay 5 Rectifier Regulator 6 Battery 7 Fuse holder assembly EB800000 ELECTRICAL ELECTRICAL COMPONENTS ...

Page 198: ...e checking switches Set the pocket tester selector to 1 Ω SWITCH CONNECTION AS SHOWN IN THIS MANUAL This manual contains connection charts like the one shown on the left showing the terminal connections of switches e g the main switch handlebar switch brake switch lighting switch etc The column on the extreme left indicates the dif ferent switch positions the top line indicates the colors of the l...

Page 199: ...switch 8 Start switch 9 Rear brake switch 10 Neutral switch 11 Sidestand switch 12 Fuse 13 Thermo switch SWITCH INSPECTION ELEC SWITCH CONTINUITY INSPECTION Refer to SWITCH INSPECTION and check for continuity between lead terminals Poor connection no continuity Correct or replace The coupler locations are circled ...

Page 200: ...7 4 1 C D I magneto 6 Main switch 10 Engine stop switch 12 C D I unit 13 Ignition coil 14 Spark plug 15 Sidestand switch IGNITION SYSTEM ELEC EB802000 IGNITION SYSTEM CIRCUIT DIAGRAM ...

Page 201: ...IGNITION SYSTEM FAILS TO OPERATE NO SPARK OR INTERMITTENT SPARK Procedure Check 1 Spark plug 2 Ignition spark gap 3 Spark plug cap resistance 4 Ignition coil 5 Pickup coil resistance 6 Source coil resistance 7 Main switch 8 Engine stop switch 9 Sidestand switch 10 Wiring connection entire ignition system Remove the following parts before trouble shooting 1 Side cover left and right 2 Seat 3 Fuel t...

Page 202: ...sconnect the spark plug cap from the spark plug SConnect the ignition checker as shown Spark plug cap STurn the main switch to ON SCheck the ignition spark gap SCheck the spark by pushing the starter switch and increase the spark gap until a misfire occurs 2 Ignition spark gap Minimum spark gap 6 mm The ignition system is not faulty MEETS SPECIFICATION 1 2 a OUT OF SPECIFICA TION OR NO SPARK 3 Spa...

Page 203: ... the primary coil has the specified re sistance 4 Ignition coil resistance Secondary coil resistance 5 68 X 8 52 kΩ 20_C BOTH MEET SPECIFICATION Tester lead Orange Terminal Tester lead Ground Terminal Replace the ignition coil OUT OF SPECIFICATION 1 2 Primary coil resistance 0 32 X 0 48 Ω 20_C 1 2 SConnect the pocket tester Ω 1k to the ignition coil SCheck the secondary has the specified re sistan...

Page 204: ...9 X 984 Ω 20_C 1 2 SCheck the pickup coil has the specified re sistance MEETS SPECIFICATION SDisconnect the source coil coupler from the wireharness SConnect the pocket tester Ω 100 to the charging coil coupler 6 Source coil resistance Source coil resistance 624 X 936 Ω 20_C 1 2 SCheck the source coil has the specified re sistance Replace the source coil OUT OF SPECIFICATION MEETS SPECIFICATION Re...

Page 205: ...itch right NO CONTINUITY CONTINUITY Refer to SWITCH INSPECTION section 9 Sidestand switch Replace the sidestand switch NO CONTINUITY CONTINUITY SCheck the connection of the entire ignition system Refer to CIRCUIT DIAGRAM 10 Wiring connection Correct POOR CONNECTIONS CORRECT Replace the C D I unit YP YP YP ...

Page 206: ...ry 5 Fuse 6 Main switch 10 Engine stop switch 11 Start switch 15 Clutch switch 16 Sidestand switch 17 Neutral relay 24 Neutral switch 38 Starter motor ELECTRIC STARTING SYSTEM ELEC EB80300 ELECTRIC STARTING SYSTEM CIRCUIT DIAGRAM ...

Page 207: ... if The transmission is in neutral the neutral relay is closed or if The clutch lever is pulled to the handlebar the clutch switch is closed and the side stand is up the sidestand switch is closed WHEN THE TRANSMISSION IS IN NEUTRAL WHEN THE SIDESTAND IS UP AND THE CLUTCH LEVER IS PULLED IN 1 Battery 2 Main fuse 3 Main switch 4 Engine stop switch 5 Neutral relay 6 Clutch switch 7 Sidestand switch ...

Page 208: ...he battery INCORRECT YP803020 TROUBLESHOOTING IF THE STARTER MOTOR FAILS TO OPERATE Procedure Check 1 Fuse 2 Battery 3 Starter motor 4 Starter relay 5 Neutral relay 6 Main switch 7 Engine stop switch 8 Neutral switch 9 Sidestand switch 10 Clutch switch 11 Start switch 12 Wiring connection entire starting system Remove the following parts before trouble shooting 1 Side cover left and right 2 Headli...

Page 209: ...he pocket tester Ω 1 and bat tery 12 V to the relay unit coupler terminals Battery lead Blue White terminal Battery lead Red White terminal 1 2 SCheck the starter relay for continuity Tester lead terminal Tester lead terminal 3 4 CONTINUITY NO CONTINUITY Replace the starter relay WARNING YP YP SA wire used as a jumper lead must have the equivalent capacity as that of the battery lead or more other...

Page 210: ...CONTINUITY Replace the neutral relay 6 Main switch Refer to SWITCH INSPECTION section CONTINUITY NO CONTINUITY Replace the main switch 7 Engine stop switch Refer to SWITCH INSPECTION section CONTINUITY NO CONTINUITY Replace the handlebar switch right 8 Neutral switch Refer to SWITCH INSPECTION section NO CONTINUITY at NEUTRAL position CONTINUITY at NEUTRAL position Replace the neutral switch 9 Sid...

Page 211: ...ONTINUITY NO CONTINUITY Replace the clutch switch 11 Start switch Refer to SWITCH INSPECTION section CONTINUITY NO CONTINUITY Replace the handlebar switch right 12 Wiring connection SCheck the connections of the entire starting system Refer to CIRCUIT DIAGRAM POOR CONNECTION Correct YP YP YP ...

Page 212: ...EMENT section in CHAPTER 3 Refer to CLUTCH REMOVAL section in CHAPTER 4 Reverse the removal procedure for installation Refer to Assembly section 7 Nm 0 7 m kg Starter motor disassembly Front bracket Washer set Rear bracket Washer set Brush holder brush Armature coil 1 1 1 1 1 1 Disassemble the parts in order Reverse the disassembly procedure for assembly 1 2 3 4 5 6 ELECTRICAL STARTING SYSTEM ELEC...

Page 213: ...ut of specification Scrape the mica to the proper value a hacksaw blade can be ground to fit The mica insulation of the commutator must be undercut to ensure proper operation of commu tator 4 Inspect Armature coil resistances installation continuity Defects Replace the starter motor If commutator is dirty clean it with sandpa per Good condition Bad condition Continuity No continuity Bad condition ...

Page 214: ...sembly Reverse the Disassembly procedure Note the following points 1 Install Brush holder 1 Align the lib on the brush holder with the slot a on the bracket before assembly 2 Install Washer set 1 Armature coil 2 3 Install Ring 1 Stator assembly 2 Washer set 3 Front bracket Apply molybdenum grease lightly on to the bearings of the starter motor Align the match marks on the yoke with the match marks...

Page 215: ...7 19 1 C D I magneto 2 Rectifier Regulator 4 Battery 5 Fuse CHARGING SYSTEM ELEC YP804000 CHARGING SYSTEM CIRCUIT DIAGRAM ...

Page 216: ...e battery fluid Clean battery terminals Recharge or replace the battery YP804010 TROUBLESHOOTING IF THE BATTERY IS NOT CHARGED Procedure Check 1 Fuse 2 Battery 3 Charging voltage 4 Stator coil resistance 5 Wiring system entire charging system Remove the following parts before trouble shooting 1 Side cover left and right 2 Seat 3 Fuse Use the special tools specified in the trouble shooting section ...

Page 217: ...ltage Charging voltage 14 5 V at 5 000 r min NOTE Use a fully charged battery OUT OF SPECIFICATION MEETS SPECIFICATION The charging circuit is not faulty Replace the battery 4 Stator coil resistance SRemove the C D I magneto coupler from wireharness SConnect the pocket tester Ω 1 to the sta tor coil Tester lead White terminal Tester lead White terminal SMeasure the stator coil resistance Stator co...

Page 218: ...7 22 5 Wiring connection Check the entire charging system for connec tions Refer to CIRCUIT DIAGRAM section CORRECT Replace the rectifier regulator POOR CONNECTION Correct CHARGING SYSTEM ELEC YP ...

Page 219: ...y 5 Fuse 6 Main switch 22 High beam indicator light 23 Meter light 26 Tail Brake light 30 Auxiliary light 34 Lights switch 36 Dimmer switch 39 Headlight LIGHTING SYSTEM ELEC EB804000 LIGHTING SYSTEM CIRCUIT DIAGRAM ...

Page 220: ...Refer to SWITCH INSPECTION section CONTINUITY NO CONTINUITY Replace the main switch YP805010 TROUBLESHOOTING IF THE HEADLIGHT AUXILIARY LIGHT HIGH BEAM INDICATOR LIGHT TAILLIGHT AND OR METER LIGHT FAIL TO COME ON Procedure Check 1 Fuse 2 Battery 3 Main switch 4 Lights switch 5 Dimmer switch 6 Wiring connection entire lighting system Remove the following parts before trouble shooting 1 Seat 2 Fuel ...

Page 221: ...TINUITY Replace the handlebar switch left 6 Wiring connection SCheck the connections of the entire lighting system Refer to WIRING DIAGRAM CORRECT Check the condition of each of the lighting system s circuits Refer to LIGHTING SYSTEM CHECK POOR CONNECTIONS Correct 1 Bulb and bulb socket Refer to SWITCH INSPECTION section CONTINUITY NO CONTINUITY Replace the bulb and or bulb socket 2 Voltage SConne...

Page 222: ...socket connector is faulty Repair 1 Bulb and bulb socket Refer to SWITCH INSPECTION section CONTINUITY 2 Voltage SConnect the pocket tester DC20V to the bulb socket coupler STurn the main switch to on STurn the lights switch to on position STurn the dimmer switch to low beam or high beam SCheck the voltage 12 V of the leads on the bulb socket connector MEETS SPECIFICATION This circuit is not fault...

Page 223: ...nd or bulb socket OUT OF SPECIFICATION The wiring circuit from main switch to bulb connector is faulty Repair 1 Bulb and bulb socket Refer to SWITCH INSPECTION section CONTINUITY 2 Voltage Connect the pocket tester DC20V to the bulb socket connector Turn the main switch to on position Turn the lights switch to on position Turn the dimmer switch to low beam or high beam Check the voltage 12 V on th...

Page 224: ... Turn indicator light left 21 Turn indicator light right 24 Neutral switch 25 Rear flasher lights 26 Tail Brake light 27 Front brake switch 28 Rear brake switch 29 Front flasher lights 31 Flasher relay 32 Horn 35 Horn switch 37 Turn switch SIGNAL SYSTEM ELEC EB806000 SIGNAL SYSTEM CIRCUIT DIAGRAM ...

Page 225: ...replace the battery 3 Main switch Refer to SWITCH INSPECTION section CONTINUITY NO CONTINUITY Replace the main switch YP806010 TROUBLESHOOTING IF THE FLASHER LIGHT BRAKE LIGHT AND OR INDICATOR LIGHT FAIL TO COME ON IF THE HORN FAILS TO SOUND Procedure Check 1 Fuse 2 Battery 3 Main switch 4 Wiring connection entire signal system SRemove the following parts before trouble shooting 1 Headlight unit 2...

Page 226: ...rness SCheck the connections of the entire signal system Refer to CIRCUIT SYSTEM WIRING DIA GRAM section CORRECT Check condition of each of the signal sys tem s circuits Refer to SIGNAL SYSTEM CHECK section POOR CONNECTION Correct YP ...

Page 227: ...d at the horn terminal MEETS SPECIFICATION 3 Horn Connect the pocket tester DC20V to the horn at the Pink terminal Turn the main switch to on Check for voltage 12V on the Pink lead to frame ground MEETS SPECIFICATION Adjust or replace horn NO CONTINUITY Replace the left handlebar switch left OUT OF SPECIFICATION The wiring circuit from the main switch to the horn is faulty Repair OUT OF SPECIFICAT...

Page 228: ...n The brake lever or brake pedal is pulled in down Check for voltage 12V of the Yellow lead on the bulb socket connector MEETS SPECIFICATION This circuit is not faulty NO CONTINUITY Replace the bulb and or bulb socket NO CONTINUITY Replace brake switch OUT OF SPECIFICATION 4 Wiring connection Wiring circuit from the main switch to the bulb socket connector is faulty Repair Refer to SIGNAL SYSTEM W...

Page 229: ...asher relay terminal 1 MEETS SPECIFICATION 4 Flasher relay SConnect the pocket tester DC20V to the flasher relay coupler STurn the main switch to on SCheck for voltage 12V on the Brown White lead at the flasher relay terminal MEETS SPECIFICATION NO CONTINUITY Replace the bulb and or bulb socket NO CONTINUITY Replace the left handlebar switch left OUT OF SPECIFICATION The wiring circuit from main s...

Page 230: ... lead and Dark green at the flasher light ter minal MEETS SPECIFICATION This circuit is not faulty OUT OF SPECIFICATION Wiring connection Wiring circuit from the turn switch to bulb socket connector is fault Repair Refer to CIRCUIT DIAGRAM 1 Bulb and bulb socket Refer to SWITCH INSPECTION section CONTINUITY 2 Neutral switch Refer to SWITCH INSPECTION section CONTINUITY NO CONTINUITY Replace the bu...

Page 231: ...tage 12V of the Sky blue lead on the neutral switch MEETS SPECIFICATION This circuit is not faulty OUT OF SPECIFICATION Check the connection of the entire signal sys tem Refer to CIRCUIT DIAGRAM 1 Thermo switch SDisconnect the thermo switch connector from the wireharness SConnect the pocket tester Ω 1 to the thermo switch lead SCheck the Terminal 1 and 3 for continuity MEETS SPECIFICATION OUT OF S...

Page 232: ... from the carburetor SConnect the pocket tester Ω 1 to the heater unit SCheck the heater unit for specificated resis tance Heater unit resistance 6 X 10 Ω 20_C MEETS SPECIFICATION 3 Wiring connection SCheck the connections of the entire signal system Refer to WIRING DIAGRAM OUT OF SPECIFICATION Replace the heater unit ...

Page 233: ...POOR MEDIUM AND HIGH SPEED PERFORMANCE 8 3 POOR SPEED PERFORMANCE 8 3 CLUTCH SLIPPING DRAGGING 8 4 FAULTY GEAR SHIFTING 8 4 OVER HEATING OR OVER COOLING 8 5 FAULTY BRAKE 8 5 FRONT FORK MALFUNCTION 8 6 INSTABLE HANDLING 8 6 STARTER MOTOR DOES NOT OPERATE 8 7 FAULTY SIGNAL AND LIGHTING SYSTEM 8 8 ...

Page 234: ......

Page 235: ...ogged air passage Improperly set pilot screw Clogged pilot air passage Improperly sealed valve seat Improperly adjusted fuel level Clogged starter jet Damaged carburetor joint Improperly tightened carburetor joint clamp hose Starter plunger malfunction Clogged emulsion heated water tube Sucked in air Air filter Clogged air filter element Improper air filter setting COMPRESSION SYSTEM Cylinder and ...

Page 236: ...witch Faulty front and or rear brake switch Faulty sidestand switch Wiring Loose battery terminal Loose coupler connection Improperly grounded Broken wireharness SR901000 POOR IDLE SPEED PERFORMANCE POOR IDLE SPEED PERFORMANCE Carburetor Improperly returned starter plunger loose or clogged pilot jet Damaged carburetor joint Improperly tightened carburetor joint clamp hose Improperly adjusted idle ...

Page 237: ...gnition system Dirty spark plug Improper heat range Faulty C D I unit Faulty pick up coil Fuel system Clogged fuel tank cap breather hole Clogged air cleaner element Clogged jet Improperly adjusted fuel level Compression system Worn cylinder Worn or seized piston ring Cylinder head gasket broken Cylinder gasket broken Carbon deposit build up Improperly adjusted valve clearance Improperly contacted...

Page 238: ... plate Swollen friction plate Match marks not aligned Engine oil Improper oil level Improper quality high viscosity Deterioration EB903000 FAULTY GEAR SHIFTING HARD SHIFTING Refer to CLUTCH DRAGGING SHIFT PEDAL DOES NOT MOVE Shift shaft Improperly adjusted shift rod Bent shift shaft Shift cam shift fork Groove jammed with impurities Seized shift fork Bent shift fork guide bar Transmission Seized t...

Page 239: ...ine oil level Improper engine oil quality High viscosity Low engine oil quality Brakes Dragging brake SR906001 FAULTY BRAKE POOR BRAKING EFFECT Front brake Worn brake pad Worn brake disc Air in brake fluid Leaking brake fluid Faulty master cylinder kit Faulty caliper seal kit Loose union bolt Broken brake hose Oily or greasy brake pad Oily or greasy brake disc Rear brake Improper brake pedal adjus...

Page 240: ...roperly installed handlebar crown Loose or overtightening steering nut Bent under bracket Improperly installed steering shaft improperly tightened ring nut Damaged bearing or ball race Front forks Uneven oil levels on both sides Uneven spring tension Broken front fork spring Fatigued front fork spring Twisted front forks Wheels Incorrect wheel balance Loose spooks Deformed wheel rim Unevenly worn ...

Page 241: ...onnection Switch Faulty main switch Faulty starter switch Faulty clutch switch Faulty neutral switch Faulty sidestand switch Faulty starting circuit cut off relay Faulty starter relay Wireharness Loose battery terminal Loosely connected coupler Improperly grounded Broken wireharness Starter motor Worn brush Faulty commutator Broken armature coil Engine Faulty starter clutch Seized engine ...

Page 242: ... life expired FLASHER DOES NOT BLINK Improperly grounded Insufficient battery capacity Faulty fuse Faulty turn switch Faulty flasher relay Broken wireharness incorrect coupler con nection Bulb burnt out FLASHER KEEPS ON Faulty flasher relay Insufficient battery capacity nearly discharged Bulb burnt out front or rear FLASHER BLINKS SLOWER Faulty flasher relay Insufficient battery capacity nearly di...

Page 243: ...r switches right 10 Engine stop switch 11 Start switch 12 C D I unit 13 Ignition coil 14 Spark plug 15 Clutch switch 16 Sidestand switch 17 Neutral relay 18 Speedometer 19 Neutral indicator light 20 Turn indicator light left 21 Turn indicator light right 22 Hi beam indicator light 23 Meter light 24 Neutral switch 25 Rear flasher lights 26 Tail Brake light 27 Front brake switch 28 Rear brake switch...

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Yamaha SR125 1997, Service Manual

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