Yamaha RAPTOR YFM50S Service Manual Download Page 110

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ENG

CAMSHAFT, ROCKER ARMS AND VALVES

12.Measure:

• spring tilt

Out of specification

→

Replace.

Spring tilt limit

Inner

2.5°/1.4 mm (2.5°/0.06 in)

EBS00241

INSTALLING THE VALVES AND VALVE
SPRINGS

1. Apply:

• molybdenum disulfide oil

(onto the valve stem and valve stem seal)

2. Install:

• valve spring seats
• valve stem seals

• valves
• valve springs
• valve spring retainers

NOTE:

Install the valve springs with the larger pitch

facing upwards.

Smaller pitch

3. Install:

• valve cotters

NOTE:

Install the valve cotters while compressing the
valve spring with the valve spring compressor

and attachment

4. To secure the valve cotters onto the valve

stem, lightly tap the valve tip with a piece of
wood.

CAUTION:

Hitting the valve tip with excessive force
could damage the valve.

Valve spring compressor

P/N. YM-04019, 90890-04019

Valve spring compressor attach-
ment

P/N. YM-04108, 90890-04108

New

Summary of Contents for RAPTOR YFM50S

Page 1: ...LIT 11616 17 13 5YF 28197 10 YFM50S SERVICE MANUAL ...

Page 2: ...by Yamaha Motor Corporation U S A First Edition April 2003 All rights reserved Any reproduction or unauthorized use without the written permission of Yamaha Motor Corporation U S A is expressly prohibited Printed in U S A LIT 11616 17 13 ...

Page 3: ...ions and sig nificant changes in specifications or procedures will be forwarded to all authorized Yamaha dealers and will appear in future editions of this manual where applicable NOTE _ Designs and specifications are subject to change without notice EBS00003 IMPORTANT INFORMATION Particularly important information is distinguished in this manual by the following notations The Safety Alert Symbol ...

Page 4: ...parts and clarify procedure steps there are exploded diagrams at the start of each removal and disassembly section 1 An easy to see exploded diagram 4 is provided for removal and disassembly jobs 2 Numbers 5 are given in the order of the 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 easy to read...

Page 5: ...limit clearance F Engine speed G Electrical data Ω V A Symbols H to M in the exploded diagrams indicate the types of lubricants and lubrication points H Apply engine oil I Apply gear oil J Apply molybdenum disulfide oil K Apply wheel bearing grease L Apply lithium soap based grease M Apply molybdenum disulfide grease Symbols N to O in the exploded diagrams indicate where to apply a locking agent N...

Page 6: ...OF CONTENTS GENERAL INFORMATION GEN INFO 1 SPECIFICATIONS SPEC 2 PERIODIC CHECKS AND ADJUSTMENTS CHK ADJ 3 ENGINE ENG 4 CARBURETOR CARB 5 DRIVE TRAIN DRIV 6 CHASSIS CHAS 7 ELECTRICAL ELEC 8 TROUBLESHOOTING TRBL SHTG 9 ...

Page 7: ... COTTER PINS 1 3 BEARINGS AND OIL SEALS 1 3 CIRCLIPS 1 3 CHECKING THE CONNECTIONS 1 4 SPECIAL TOOLS 1 5 CHAPTER 2 SPECIFICATIONS GENERAL SPECIFICATIONS 2 1 ENGINE SPECIFICATIONS 2 4 CHASSIS SPECIFICATIONS 2 11 ELECTRICAL SPECIFICATIONS 2 12 TIGHTENING TORQUES 2 14 ENGINE TIGHTENING TORQUES 2 14 CHASSIS TIGHTENING TORQUES 2 15 HOW TO USE THE CONVERSION TABLE 2 17 GENERAL TIGHTENING TORQUE SPECIFICA...

Page 8: ...CKING THE IGNITION TIMING 3 14 MEASURING THE COMPRESSION PRESSURE 3 15 CHECKING THE ENGINE OIL LEVEL 3 17 CHANGING THE ENGINE OIL 3 18 CLEANING THE AIR FILTER ELEMENT 3 19 CLEANING THE SPARK ARRESTER 3 20 CHASSIS 3 22 CHECKING THE FRONT AND REAR BRAKE SHOES 3 22 ADJUSTING THE FRONT BRAKE 3 22 ADJUSTING THE REAR BRAKE 3 23 CHECKING THE FINAL GEAR OIL LEVEL 3 24 CHANGING THE FINAL GEAR OIL 3 24 CHEC...

Page 9: ...HEAD 4 10 CAMSHAFT ROCKER ARMS AND VALVES 4 12 REMOVING THE ROCKER ARMS AND CAMSHAFT 4 14 REMOVING THE VALVES AND VALVE SPRINGS 4 14 CHECKING THE CAMSHAFT 4 15 CHECKING THE ROCKER ARMS AND ROCKER ARM SHAFTS 4 15 CHECKING THE VALVES AND VALVE SPRINGS 4 17 INSTALLING THE VALVES AND VALVE SPRINGS 4 21 INSTALLING THE CAMSHAFT AND ROCKER ARMS 4 22 CYLINDER AND PISTON 4 23 REMOVING THE PISTON 4 24 CHECK...

Page 10: ...PPER LEVER 4 48 INSTALLING THE STOPPER LEVER 4 48 INSTALLING THE SHIFT SHAFT 4 48 CRANKCASE 4 49 CRANKCASE BEARINGS 4 50 SEPARATING THE CRANKCASE 4 51 CHECKING THE TIMING CHAIN 4 51 CHECKING THE BEARINGS AND OIL SEALS 4 52 CHECKING THE CRANKCASE 4 52 INSTALLING THE BEARINGS 4 52 ASSEMBLING THE CRANKCASE 4 53 CRANKSHAFT 4 54 CHECKING THE CRANKSHAFT 4 55 INSTALLING THE CRANKSHAFT 4 55 TRANSMISSION 4...

Page 11: ...HE REAR AXLE FINAL DRIVE ASSEMBLY 6 8 DISASSEMBLING THE REAR AXLE HOUSING 6 9 DISASSEMBLING THE FINAL GEAR CASE 6 9 CHECKING THE REAR AXLE 6 10 CHECKING THE DRIVE SHAFT 6 10 CHECKING THE REAR AXLE HOUSING AND FINAL DRIVE ASSEMBLY 6 10 ASSEMBLING THE FINAL GEAR CASE 6 11 ASSEMBLING THE REAR AXLE HOUSING 6 11 INSTALLING THE REAR AXLE FINAL DRIVE ASSEMBLY 6 12 INSTALLING THE NUTS 6 13 CHAPTER 7 CHASS...

Page 12: ...E LEVER ASSEMBLY 7 18 STEERING STEM 7 19 REMOVING THE STEERING STEM 7 20 CHECKING THE STEERING STEM 7 20 INSTALLING THE STEERING STEM 7 20 INSTALLING THE LOCK WASHER 7 20 TIE RODS AND STEERING KNUCKLES 7 21 REMOVING THE TIE RODS 7 22 CHECKING THE TIE RODS 7 22 CHECKING THE STEERING KNUCKLES 7 22 INSTALLING THE TIE RODS 7 23 FRONT SHOCK ABSORBER ASSEMBLIES AND FRONT SWINGARM 7 24 REMOVING THE FRONT...

Page 13: ... TROUBLESHOOTING 8 8 ELECTRIC STARTING SYSTEM 8 12 CIRCUIT DIAGRAM 8 12 STARTING CIRCUIT OPERATION 8 13 TROUBLESHOOTING 8 14 STARTER MOTOR 8 18 CHECKING THE STARTER MOTOR 8 19 ASSEMBLING THE STARTER MOTOR 8 20 CHARGING SYSTEM 8 21 CIRCUIT DIAGRAM 8 21 TROUBLESHOOTING 8 22 SIGNAL SYSTEM 8 24 CIRCUIT DIAGRAM 8 24 TROUBLESHOOTING 8 25 CHECKING THE SIGNALING SYSTEM 8 26 CHAPTER 9 TROUBLESHOOTING START...

Page 14: ...2 FAULTY DRIVE TRAIN 9 3 FAULTY GEAR SHIFTING 9 4 HARD SHIFTING 9 4 SHIFT LEVER DOES NOT MOVE 9 4 JUMPS OUT GEAR 9 4 CLUTCH SLIPPING DRAGGING 9 4 CLUTCH SLIPPING 9 4 CLUTCH DRAGGING 9 4 OVERHEATING 9 4 OVERHEATING 9 4 FAULTY BRAKE 9 5 POOR BRAKING EFFECT 9 5 SHOCK ABSORBER MALFUNCTION 9 5 MALFUNCTION 9 5 UNSTABLE HANDLING 9 5 UNSTABLE HANDLING 9 5 ...

Page 15: ...TION EBS00010 VEHICLE IDENTIFICATION NUMBER The vehicle identification number 1 is stamped into the left side of the frame EBS00011 MODEL LABEL The model label 1 is affixed to the frame This information will be needed to order spare parts MACHINE IDENTIFICATION ...

Page 16: ...ll of the parts and place them in trays in the order of dis assembly This will speed up assembly and allow for the correct installation of all parts 5 Keep all parts away from any source of fire EBS00014 REPLACEMENT PARTS 1 Use only genuine Yamaha parts for all replacements Use oil and grease recom mended by Yamaha for all lubrication jobs Other brands may be similar in function and appearance but...

Page 17: ...sible When installing oil seals lubricate the oil seal lips with a light coat of lithium soap based grease Oil bearings liberally when installing if appro priate 1 Oil seal CAUTION _ Do not spin the bearing with compressed air because this will damage the bearing surfaces 1 Bearing EBS00018 CIRCLIPS Before reassembly check all circlips carefully and replace damaged or distorted circlips Always rep...

Page 18: ...t sev eral times 3 Check all connections Loose connection Connect properly NOTE _ If the pin 1 on the terminal is flattened bend it up 4 Connect lead coupler connector NOTE _ Make sure all connections are tight 5 Check continuity with the pocket tester NOTE _ If there is no continuity clean the terminals When checking the wire harness perform steps 1 to 3 As a quick remedy use a contact revitalize...

Page 19: ...ept for US and CDN P N 90890 Tool No Tool name Function Illustration Bolt 90890 01085 Weight 90890 01084 Set YU 01083 A Slide hammer bolt M8 weight set These tools are used to remove the rocker arm shaft 90890 01189 YM 01189 Flywheel puller This tool is needed to remove the rotor 90890 01304 YU 01304 Piston pin puller set This tool is used to remove the piston pin 90890 01311 YM 08035 Tappet adjus...

Page 20: ...sh 90890 01701 YS 01880 A Sheave holder This tool is needed to hold the rotor when removing or installing the rotor nut Gauge 90890 03081 YU 33223 Adapter 90890 04082 Compression gauge Adapter These tools are needed to measure engine compression 90890 03112 YU 03112 C Pocket tester This instrument is needed for checking the electrical system 90890 03113 Engine tachometer This tool is needed for ob...

Page 21: ... remover 5 mm This tool is needed to remove and install the valve guide 90890 04098 YM 04098 Valve guide installer 5 mm This tool is needed to install the valve guide 90890 04099 Valve guide reamer 5 mm This tool is needed to rebore the new valve guide 90890 04100 Clutch holder This tool is needed to hold the clutch boss when removing or installing the clutch boss nut 90890 04129 YM 04129 Pinion g...

Page 22: ...faces etc YM 01363 27 mm hexagon wrench This tool is needed to loosen and tighten the middle driven pinion gear bearing retainer YM 34487 Dynamic spark tester This instrument is necessary for checking the ignition system components YU 8036 B Inductive self powered tachometer This tool is needed for observing engine rpm Tool No Tool name Function Illustration ...

Page 23: ...nt 49 cm3 Bore stroke 39 0 41 4 mm 1 54 1 63 in Compression ratio 10 0 1 Standard compression pressure at sea level 1 200 kPa 12 0 kg cm2 170 6 psi at 1 000 r min Starting system Electric starter Lubrication system Wet sump Oil type or grade Engine oil API service SE SF SG type or higher Final gear oil SAE 80API GL 4 Hypoid gear oil Oil capacity Engine oil Periodic oil change 0 80 L 0 70 Imp qt 0 ...

Page 24: ... system Shaft drive Secondary reduction ratio 19 18 34 10 3 588 Operation Left hand operation Gear ratio 1st gear 38 14 2 714 Chassis Frame type Steel tube frame Caster angle 1 0 Camber angle 2 0 Kingpin angle 10 Trail 3 4 mm 0 13 in Tread STD front 630 mm 24 80 in rear 665 mm 26 18 in Toe in 0 10 mm 0 0 39 in Tire Type Tubeless Size front AT16 7 7 rear AT16 8 7 Manufacturer front DUNLOP rear DUNL...

Page 25: ...arm Rear suspension Swingarm Shock absorber Front shock absorber Coil spring oil damper Rear shock absorber Coil spring oil damper Wheel travel Front wheel travel 57 mm 2 24 in Rear wheel travel 56 mm 2 20 in Electrical Ignition system C D I Generator system A C magneto Battery type 12N7D 3B Battery capacity 12 V 7 AH Bulb wattage quantity Neutral indicator light 12 V 1 7 W 1 Item Standard ...

Page 26: ...0 01 mm 0 0004 in Camshaft Drive method Chain drive Left Cam dimensions Intake A 25 300 25 310 mm 0 9961 0 9965 in 25 200 mm 0 9921 in B 20 994 21 094 mm 0 8265 0 8305 in 20 894 mm 0 8226 in Exhaust A 25 301 25 311 mm 0 9961 0 9965 in 25 201 mm 0 9922 in B 21 021 21 121 mm 0 8276 0 8315 in 20 921 mm 0 8237 in Camshaft runout limit 0 03 mm 0 0012 in Timing chain Timing chain type No of links Bush c...

Page 27: ...6 9 mm 0 6575 0 6654 in B face width IN 1 10 2 30 mm 0 0433 0 0906 in EX 1 30 2 40 mm 0 0512 0 0945 in C seat width IN 0 9 1 1 mm 0 0354 0 0433 in 1 6 mm 0 0630 in EX 0 9 1 1 mm 0 0354 0 0433 in 1 6 mm 0 0630 in D margin thickness IN 0 5 0 9 mm 0 0197 0 0354 in 1 6 mm 0 0630 in EX 0 6 1 0 mm 0 0236 0 0394 in 1 6 mm 0 0630 in Stem outside diameter IN 4 975 4 990 mm 0 1959 0 1965 in 4 950 mm 0 1949 ...

Page 28: ... 0630 in EX 0 9 1 1 mm 0 0354 0 0433 in 1 6 mm 0 0630 in Valve spring Free length IN 32 00 mm 1 26 in 30 40 mm 1 20 in EX 32 00 mm 1 26 in 30 40 mm 1 20 in Compressed pressure installed IN 136 158 N at 24 6 mm 13 87 16 11 kg 30 57 35 52 lb at 0 97 in EX 136 158 N at 24 6 mm 13 87 16 11 kg 30 57 35 52 lb at 0 97 in Tilt limit IN 2 5 1 4 mm 2 5 0 06 in EX 2 5 1 4 mm 2 5 0 06 in Direction of winding ...

Page 29: ... 0 5119 0 5123 in 13 043 mm 0 5135 in Piston pin outside diameter 12 996 13 000 mm 0 5117 0 5118 in 12 976 mm 0 5109 in Piston rings Top ring Type Barrel Dimensions B T 1 0 1 7 mm 0 0394 0 0669 in End gap installed 0 08 0 20 mm 0 0031 0 0079 in 0 45 mm 0 0177 in Side clearance installed 0 030 0 065 mm 0 0012 0 0026 in 0 12 mm 0 0047 in 2nd ring Type Taper Dimensions B T 1 0 1 7 mm 0 0394 0 0669 in...

Page 30: ... in Big end side clearance D 0 10 0 40 mm 0 0039 0 0157 in 0 50 mm 0 0197 in Big end radial clearance E 0 004 0 019 mm 0 0002 0 0007 in Small end free play F 0 80 1 00 mm 0 0315 0 0394 in 1 50 mm 0 0591 in Clutch Friction plate 1 with black color marking Thickness 2 92 3 08 mm 0 115 0 121 in 2 90 mm 0 114 in Quantity 4 Friction plate 2 Thickness 2 92 3 08 mm 0 115 0 121 in 2 90 mm 0 114 in Quantit...

Page 31: ...n Clutch stall revolution 3 000 3 200 r min Transmission Main axle deflection limit 0 08 mm 0 0031 in Drive axle deflection limit 0 08 mm 0 0031 in Shifter Shifter type Shift drum and guide bar Carburetors I D mark 5YF1 00 Main jet M J 72 5 Air jet A J 1 2 Jet needle J N 3PZ13 2 Needle jet N J D 8M Cutaway C A 3 Pilot outlet P O 0 7 Pilot jet P J 15 Valve seat size V S 1 2 Fuel level F L 4 0 5 0 m...

Page 32: ...106 mm 0 0042 in Oil pump housing to inner rotor and outer rotor clearance 0 06 0 10 mm 0 0024 0 0039 in 0 17 mm 0 0067 in Shaft drive Middle gear backlash 0 17 0 31 mm 0 007 0 012 in Final gear backlash 0 17 0 31 mm 0 007 0 012 in Lubrication chart Item Standard Limit Pressure feed Splashed scavenge Crankshaft pin Camshaft Rocker arm Valve Timing chain area Oil strainer Oil pump Piston Piston pin...

Page 33: ...material Steel Rim runout limit radial 2 0 mm 0 08 in lateral 2 0 mm 0 08 in Front drum brake Type Leading trailing Brake drum inside diameter 110 0 mm 4 33 in 110 5 mm 4 35 mm Lining thickness 4 0 mm 0 16 in 2 0 mm 0 08 in Shoe spring free length 54 0 mm 2 13 in Rear drum brake Type Leading trailing Brake drum inside diameter 130 0 mm 5 12 in 130 5 mm 5 14 in Lining thickness 4 0 mm 0 16 in 2 0 m...

Page 34: ... manufacturer 2JN YAMAHA Minimum spark gap 6 mm 0 24 in Primary winding resistance 0 18 0 28 Ω at 20 C 68 F Secondary winding resistance 6 32 9 48 kΩ at 20 C 68 F Spark plug cap Type Resin Resistance 10 kΩ Charging system Type A C magneto Model manufacturer F2FM YAMAHA Nominal output 14 V 45 W at 5 000 r min Charging coil resistance color 0 72 1 08 Ω at 20 C 68 F White Black Lighting coil resistan...

Page 35: ... 4 22 N 330 430 gf 11 66 15 19 oz Commutator diameter 16 5 mm 0 65 in 15 5 mm 0 61 in Mica undercut 1 mm 0 04 in Starter relay Model manufacturer MS5E 661 JIDECO Amperage rating 100 A Coil winding resistance 4 18 4 62 Ω at 20 C 68 F Starting circuit cut off relay Model manufacturer ACA12115 3 MATSUSHITA Coil resistance 72 88 Ω at 20 C 68 F Diode Yes Circuit breakers Type Fuse Amperage for individu...

Page 36: ...t M6 2 10 1 0 7 2 Muffler Bolt M8 2 25 2 5 18 Spark arrester Screw M6 2 8 0 8 5 8 Muffler purging bolt Bolt M6 1 10 1 0 7 2 Crankcase Screw M6 9 7 0 7 5 1 Crankcase cylinder head Stud bolt M6 4 10 1 0 7 2 Main axle bearing retainer Screw M6 2 8 0 8 5 8 LT Drive axle middle drive pinion gear assembly plate Bolt M6 3 10 1 0 7 2 Clutch cover Screw M6 3 7 0 7 5 1 C D I magneto cover Screw M6 9 7 0 7 5...

Page 37: ...ng stem bushing and frame M8 23 2 3 17 Handlebar holder and steering stem M8 20 2 0 14 Throttle lever and housing M8 8 0 8 5 8 Front wheel and brake drum M8 28 2 8 20 Front axle and brake drum M14 70 7 0 50 Front brake camshaft and camshaft lever M6 9 0 9 6 5 Rear brake camshaft and camshaft lever M6 9 0 9 6 5 Rear axle and nut M28 See NOTE Rear wheel and wheel hub M8 28 2 8 20 Rear axle and wheel...

Page 38: ... 13 0 m kg 94 ft lb while holding the inside nut 4 Loosen the inside nut to 160 Nm 16 0 m kg 115 ft lb while holding the outside nut Final gear oil drain plug M14 23 2 3 17 Final gear case bearing retainer M55 80 8 0 58 LT Final drive pinion gear and bearing M20 12 1 2 8 7 LT Rear axle housing bearing retainer M58 110 11 0 80 LT Part to be tightened Thread size Tightening torque Remarks Nm m kg ft...

Page 39: ...nless otherwise specified tightening torque specifications require clean dry threads Com ponents should be at room temperature A Distance between flats B Outside thread diameter Ex METRIC MULTIPLIER IMPERIAL mm 0 03937 in 2 mm 0 03937 0 08 in METRIC TO IMPERIAL Torque Metric unit Multiplier Imperial unit 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 0...

Page 40: ...Timing chain tensioner E Intake side timing chain guide E Oil pump assembly E Starter idle gear shaft M Starter wheel gear E Primary driven gear spacer E Clutch push rod oil seal E Drive axle 1st wheel gear M Drive axle dog splines M Drive axle dog shift fork groove E Middle drive driven pinion gear E Shift drum E Shift fork guide bar O ring E Shift shaft E Shift shaft washer LS Middle driven pini...

Page 41: ...2 19 SPEC LUBRICATION POINTS AND LUBRICANT TYPES Final gear case and rear axle housing mating surface Sealant Quick Gasket Yamaha Bond No 1215 Lubrication points Lubricant ...

Page 42: ...2 20 SPEC OIL FLOW DIAGRAMS EBS00026 OIL FLOW DIAGRAMS 1 Camshaft 2 Crankshaft 3 Main axle 4 Drive axle ...

Page 43: ...2 21 SPEC OIL FLOW DIAGRAMS 1 Oil pump 2 Oil strainer ...

Page 44: ... breather hose 6 Crankcase breather hose 7 Starter relay 8 Starting circuit cut off relay 9 Positive battery lead 0 Wire harness A Negative battery lead B Rectifier regulator C Engine stop switch lead frame end D Battery breather hose E Starter motor lead F Fuel overflow hose G Right front brake cable H Left front brake cable I Engine stop switch frame ...

Page 45: ...o slack or bends in the hose Do not route the hose over the throttle cable Ê Route the final gear case breather hose and crankcase breather hose to the right of the ignition coil Ë Align the white tape of the wire harness with the bracket Ì 200 mm 7 87 in Í To starter motor Î Fasten the engine stop switch lead frame end to the frame with a plastic band Ï Pass the final gear case breather hose thro...

Page 46: ...LE ROUTING Ñ Fasten the carburetor air vent hose with a plastic band Be sure to not pinch the hose Install the plastic band with the buckle facing backward and the end inward Ò Route the cables under the frame Ó 45 ...

Page 47: ...s 3 Ignition coil 4 Handlebar switch lead 5 Rear brake switch lead 6 Neutral indicator light lead 7 Main switch 8 C D I unit 9 Fuel hose 0 Crankcase breather hose A Final gear case breather hose B Fuel tank breather hose C Throttle cable D Front brake cables ...

Page 48: ...nkcase breather hose over the wire harness Fasten the hoses with a plastic band Be sure to not pinch the hoses Pass the ends of the hoses between the frame and bracket Ë Fasten the rear brake cable and wire harness near the ignition coil with a plastic locking tie Ì Do not fasten the main switch lead Í Fasten the crankcase breather hose and final gear case breather hose with a plastic band Î Face ...

Page 49: ...OUTING 1 Rear brake switch 2 Rear brake cable 3 Left front brake cable 4 Right front brake cable 5 Throttle cable 6 Fuel tank breather hose 7 Negative battery lead 8 Main fuse 9 Positive battery lead 0 Handlebar switch ...

Page 50: ... the hole Ë To wire harness Ì To starter relay Í Fasten the handlebar switch lead and rear brake switch lead with a plastic band Î Connect the negative battery lead to the battery so that the lead is routed to the side of the battery Ï Connect the positive battery lead to the battery so that the lead contacts the battery case ...

Page 51: ...ake switch lead 6 Air filter joint 7 Neutral indicator light lead 8 Right front brake cable 9 Left front brake cable È Route the front brake cables to the left of the steering stem Route the left front brake cable to the right of the air filter joint Route the right front brake cable to the left of the air filter joint ...

Page 52: ...ion Adjust gap and clean Replace if necessary Air filter element Clean Replace if necessary Every 20 40 hours more often in wet or dusty areas Carburetor Check idle speed choke lever operation Adjust if necessary Crankcase breather system Check breather hose for cracks or damage Replace if necessary Exhaust system Check for leakage Tighten if necessary Replace gasket if necessary Spark arrester Cl...

Page 53: ...ts in the order listed 1 Seat 1 NOTE _ Pull back the seat lock lever than pull up on the rear of the seat 2 Front panel 1 3 Fuel tank breather hose 1 4 Handlebar cover 1 NOTE _ When installing the handlebar cover pass the fuel tank breather hose through the hole in the handlebar cover 5 Neutral indicator light connectors 2 Disconnect For installation reverse the removal pro cedure ...

Page 54: ... 0 7 m kg 5 1 ft Ib Order Job Part Q ty Remarks Removing the front fender Remove the parts in the order listed Seat and front panel Refer to SEAT AND FRONT PANEL 1 Fuel tank top panel 1 2 Air cleaner joint clamp screw 1 Loosen 3 Main switch 1 4 Front fender 1 For installation reverse the removal pro cedure ...

Page 55: ... 7 7 Order Job Part Q ty Remarks Removing the rear fender and foot rest boards Remove the parts in the order listed Seat Refer to SEAT AND FRONT PANEL Front fender Refer to FRONT FENDER 1 Battery band 1 2 Main fuse 1 3 Negative battery lead 1 Disconnect CAUTION _ First disconnect the negative lead then disconnect the positive lead 4 Positive battery lead 1 Disconnect 5 Battery breather hose 1 Disc...

Page 56: ... 1 ft Ib T R 7 Nm 0 7 m kg 5 1 ft Ib T R 7 Nm 0 7 m kg 5 1 ft Ib T R 7 Nm 0 7 m kg 5 1 ft Ib 7 7 Order Job Part Q ty Remarks 6 Battery 1 7 Footrest board 2 8 Rear fender 1 For installation reverse the removal pro cedure SEAT FENDERS AND FUEL TANK ...

Page 57: ...ving the fuel tank Remove the parts in the order listed Seat and front panel Refer to SEAT AND FRONT PANEL Front fender Refer to FRONT FENDER 1 Fuel hose 1 Disconnect NOTE _ Before disconnecting the fuel hose turn the fuel cock to OFF 2 Fuel tank 1 For installation reverse the removal pro cedure ...

Page 58: ...er 2 on the crankcase When the T mark is aligned with the sta tionary pointer the piston is at the Top Dead Center TDC NOTE Be sure to align the alignment mark 3 on the camshaft sprocket with the alignment mark 4 on the cylinder head c Turn the crankshaft counterclockwise to align the camshaft sprocket alignment mark 5 and alignment tab 6 with the adjuster 7 as shown in the illustration d Tighten ...

Page 59: ...tappet cover exhaust tappet cover camshaft sprocket cover Refer to CYLINDER HEAD in chapter 4 2 Measure valve clearance Out of specification Adjust a Turn the crankshaft counterclockwise with a wrench b Align the T mark 1 on the rotor with the stationary pointer 2 on the crankcase When the T mark is aligned with the sta tionary pointer the piston is at the Top Dead Center TDC Valve clearance cold ...

Page 60: ...turn c Measure the valve clearance using a thick ness gauge 5 3 Adjust valve clearance a Loosen the locknut 1 b Insert a thickness gauge 2 between the adjuster end and the valve end c Turn the adjuster 3 clockwise or counter clockwise with the tappet adjusting tool 4 until the proper clearance is obtained d Hold the adjuster to prevent it from moving and then tighten the locknut e Measure the valv...

Page 61: ...warm up for sev eral minutes 2 Attach engine tachometer 1 to the spark plug lead 3 Measure engine idling speed Out of specification Adjust Inductive self powered tachome ter P N YU 8036 B Engine tachometer P N 90890 03113 Engine idling speed 1 750 1 850 r min 4 Adjust engine idling speed a Turn the throttle stop screw 1 in or out until the specified idling speed is obtained 5 Detach engine tachome...

Page 62: ...Measure throttle lever free play a Out of specification Adjust 2 Adjust throttle lever free play a Pull back the adjuster cover 1 b Loosen the locknut 2 on the carburetor side c Turn the adjuster 3 in or out until the cor rect free play is obtained d Tighten the locknut 2 e Push in the adjuster cover 1 WARNING _ After adjusting the free play turn the han dlebar to the right and left to make sure t...

Page 63: ...adjuster 2 in or out until the speci fied speed limiter length is obtained c Tighten the locknut WARNING _ Particularly for a beginner rider the speed limiter should be screwed in com pletely Screw it out little by little as their riding technique improves Never remove the speed limiter for a beginning rider For proper throttle lever operation do not turn out the adjuster more than 12 0 mm 0 47 in...

Page 64: ...eplace Normal color is a medium to light tan color 4 Clean spark plug with a spark plug cleaner or wire brush Standard spark plug CR7HS NGK 5 Measure spark plug gap a Use a wire gauge or thickness gauge Out of specification Regap 6 Tighten spark plug NOTE _ Before installing a spark plug clean the gasket surface and plug surface Spark plug gap 0 6 0 7 mm 0 024 0 028 in T R 13 Nm 1 3 m kg 9 4 ft lb...

Page 65: ...rk plug lead 3 Check ignition timing a Warm up the engine and keep it at the specified speed b Visually check the stationary pointer 1 to verify it is within the required firing range 2 indicated on the rotor Incorrect firing range Check the pickup coil 4 Detach timing light engine tachometer 5 Install C D I magneto cover Refer to C D I MAGNETO in chapter 4 Inductive self powered tachome ter P N Y...

Page 66: ...isconnect spark plug cap 4 Remove spark plug CAUTION _ Before removing a spark plug use com pressed air to blow away any dirt accumu lated in the spark plug well to prevent it from falling into the cylinder 5 Attach adapter compression gauge 1 6 Measure compression pressure Out of specification Refer to steps c and d Compression gauge P N YU 33223 90890 03081 Adapter P N 90890 04082 Compression pr...

Page 67: ...der head valve surfaces and piston crown for carbon deposits Carbon deposits Eliminate d If the compression pressure is below the minimum specification squirt a few drops of oil into the cylinder and measure again Refer to the following table 7 Install spark plug 8 Connect spark plug cap Compression pressure with oil applied into the cylinder Reading Diagnosis Higher than without oil Piston ring s...

Page 68: ... the oil cools down before removing the dipstick b Screw the dipstick 1 completely out and wipe the dipstick clean then just rest the dipstick in the hole c Pull up the dipstick and check the oil level whether or not it is between maximum a and minimum level b d If the level is lower add the oil up to the proper level NOTE _ Recommended oil classification API Service SE SF SG type or equiva lent e...

Page 69: ...se 5 Check engine oil drain bolt gasket Damage Replace 6 Install engine oil drain bolt 1 along with the gasket 7 Fill crankcase with the specified amount of the recom mended engine oil 8 Install dipstick 9 Start the engine warm it up for several min utes and then turn it off 10 Check engine for engine oil leaks 11 Check engine oil level Refer to CHECKING THE ENGINE OIL LEVEL Quantity Total amount ...

Page 70: ...emove air filter cover 1 1 1 3 Disconnect rubber band 1 4 Remove air filter element guide 2 air filter element 3 CAUTION _ The engine should never be run without the air filter excessive piston and or cylinder wear may result 5 Check air filter element Damaged Replace 6 Clean air filter element a Wash the element gently but thoroughly in solvent WARNING _ Use a cleaning solvent which is designed t...

Page 71: ...r filter element guide 8 Connect rubber band 9 Install air filter cover NOTE _ Make sure its sealing surface matches the sealing surface of the case so there is no air leak 10 Install front panel Refer to SEAT FENDERS AND FUEL TANK CLEANING THE SPARK ARRESTER 1 Clean spark arrester WARNING Select a well ventilated area free of com bustible materials Always let the exhaust system cool before perfor...

Page 72: ... muffler and align the screw holes e Insert the screw and tighten it f Remove the purging bolt 3 g Start the engine and rev it up approximately twenty times while momentarily creating exhaust system back pressure by blocking the end of the muffler with a shop towel h Stop the engine and allow the exhaust pipe to cool i Install the purging bolt 3 and tighten it T R Screw 8 Nm 0 8 m kg 5 8 ft lb T R...

Page 73: ...adjusting the front brake the front brake linings should be checked CAUTION _ Proper lever free play is essential to avoid excessive brake drag 1 Measure front brake lever free play a Out of specification Adjust 2 Adjust front brake lever free play a Loosen the locknuts 1 b Turn the adjusters 2 in or out until the specified front brake lever free play is obtained NOTE Make sure that the difference...

Page 74: ...ever side b Turn the adjuster 3 in or out until the speci fied rear brake lever free play is obtained drum side c Tighten the locknut NOTE If the free play cannot be adjusted here adjust if at the lever side of the cable Second step a Loosen the locknut 1 b Turn the adjuster 2 in or out until the speci fied rear brake lever free play is obtained lever side c Tighten the locknut WARNING _ After thi...

Page 75: ... proper level CAUTION _ Take care not allow foreign material to enter the final gear case 4 Install dipstick Recommended oil SAE80 API GL 4 Hypoid gear oil 1 a b EBS00102 CHANGING THE FINAL GEAR OIL 1 Place the machine on a level surface 2 Place a receptacle under the final gear case 3 Remove dipstick 1 final gear oil drain plug 2 4 Drain final gear oil 5 Install final gear oil drain plug NOTE _ C...

Page 76: ...to CHECKING THE FINAL GEAR OIL LEVEL 8 Install dipstick Total amount 0 12 L 0 11 Imp qt 0 13 US qt Recommended oil SAE80 API GL 4 Hypoid gear oil EBS00105 CHECKING THE SWINGARM DUST BOOT 1 Remove C D I magneto cover Refer to C D I MAGNETO in chapter 4 2 Check dust boot 1 Damage Replace Refer to REAR SHOCK ABSORBER AND REAR SWINGARM in chapter 7 3 Install C D I magneto cover Refer to C D I MAGNETO ...

Page 77: ...he left and or right until it stops completely then slightly move the handlebar from left to right Tie rod end has any vertical play Replace the tie rod end s Refer to STEERING SYSTEM in chapter 7 4 Raise the front end of the machine so that there is no weight on the front wheels 5 Check knuckles and or wheel bearings Move the wheels laterally back and forth Excessive free play Replace the follow ...

Page 78: ...tly opposite one another f Measure the width É between the marks g Calculate the toe in using the formula given below h If the toe in is incorrect adjust it Ê Forward 3 Adjust toe in WARNING _ Be sure that both tie rods are turned the same amount If not the machine will drift right or left even though the handlebar is positioned straight This may lead to mis handling and an accident After setting ...

Page 79: ... so that A and B are equal EBS00109 CHECKING THE FRONT AND REAR SHOCK ABSORBERS 1 Place the machine on a level surface 2 Check damper rod 1 Scratch damage Replace as a set oil leakage Excessive oil leakage Replace as a set Refer to FRONT SHOCK ABSORBER ASSEMBLIES AND FRONT SWINGARM and REAR SHOCK ABSORBER AND REAR SWINGARM in chapter 7 3 Check operation Pump the shock absorbers up and down for sev...

Page 80: ...re Front 20 kPa 0 20 kgf cm2 2 9 psi Rear 20 kPa 0 20 kgf cm2 2 9 psi 2 Tire pressure below the minimum speci fication could cause the tire to dislodge from the rim under severe riding condi tions The following are minimums Front 17 kPa 0 17 kgf cm2 2 5 psi Rear 17 kPa 0 17 kgf cm2 2 5 psi 3 Use no more than Front 250 kPa 2 5 kgf cm2 36 psi Rear 250 kPa 2 5 kgf cm2 36 psi when seating the tire bea...

Page 81: ... second reading WARNING _ Uneven or improper tire pressure may adversely affect the handling of this machine and may cause loss of control Maintain proper tire pressures Set tire pressures when the tires are cold Tire pressures must be equal in both front tires and equal in both rear tires Cold tire pressure Front Rear Standard 20 kPa 0 20kgf cm2 2 9 psi 20 kPa 0 20kgf cm2 2 9 psi Minimum 17 kPa 0...

Page 82: ...ification replace the tire immediately Tire wear limit a Front and rear 3 mm 0 12 in EBS00116 CHECKING THE WHEELS 1 Check wheel 1 Damage bends Replace NOTE _ Always balance the wheel when a tire or wheel has been changed or replaced WARNING _ Never attempt even small repairs to the wheel Ride conservatively after installing a tire to allow it to seat itself properly on the rim ...

Page 83: ...a damaged cable as soon as possi ble 1 Check cable sheath Damage Replace 2 Check cable operation Unsmooth operation Lubricate or replace NOTE _ Hold the cable end up and apply several drops of lubricant to the cable Recommended lubricant Lithium soap base grease EBS00118 LUBRICATING THE LEVERS STEERING SHAFT AND STEERING KNUCKLES Lubricate the pivoting point and metal to metal moving parts of the ...

Page 84: ...O NOT SMOKE when charging or han dling batteries KEEP BATTERIES AND ELECTROLYTE OUT OF REACH OF CHILDREN Avoid bodily contact with electrolyte as it can cause severe burns or permanent eye injury FIRST AID IN CASE OF BODILY CONTACT EXTERNAL Skin Wash with water Eyes Flush with water for 15 minutes and get immediate medical attention INTERNAL Drink large quantities of water or milk fol lowed with m...

Page 85: ...tilled water Tap water con tains minerals which are harmful to the bat tery b a 5 Check specific gravity Less than 1 280 Recharge the battery Specific gravity 1 280 at 20 C 68 F 6 Charge battery WARNING _ Do not quick charge a battery CAUTION _ Loosen the battery sealing caps Make sure the battery breather hose and battery vent are free of obstructions To ensure maximum performance always charge a...

Page 86: ...sure to turn off the battery charger Make sure the battery charger lead clips are in full contact with the battery termi nal and that they are not shorted A cor roded battery charger lead clip may generate heat in the contact area and a weak clip spring may cause sparks If the battery becomes hot to the touch at any time during the charging process disconnect the battery charger and let the batter...

Page 87: ...ned so as to allow electro lyte or hydrogen gas from the battery to contact the frame the machine and its fin ish may be damaged NOTE Refer to CABLE ROUTING in chapter 2 10 Check battery terminals Dirt Clean with a wire brush Loose connection Connect properly 11 Connect battery leads to the battery terminals CAUTION _ First connect the positive battery lead 1 and then the negative battery lead 2 1...

Page 88: ...UEL TANK fuse holder 1 2 Check fuse a Connect the pocket tester to the fuse and check the continuity NOTE _ Set the pocket tester selector to Ω 1 b If the pocket tester indicates replace the fuse Pocket tester P N YU 03112 C 90890 03112 3 Replace blown fuse a Set the main switch to OFF b Install a new fuse of the correct amperage c Set on the switches to verify if the electrical circuit is operati...

Page 89: ...n amperage rating other than that specified Improvising or using a fuse with the wrong amperage rat ing may cause extensive damage to the electrical system cause the ignition sys tems to malfunction and could possibly cause a fire 4 Install seat Refer to SEAT FENDERS AND FUEL TANK Items Amperage rating Q ty Main 5 A 1 Reserve 5 A 1 ...

Page 90: ... Part Q ty Remarks Removing the exhaust pipe muffler breather hose and leads Remove the parts in the order listed Rear fender Refer to SEAT FENDERS AND FUEL TANK in chapter 3 1 Exhaust pipe muffler 1 2 Exhaust pipe gasket 1 3 Spark plug lead 1 4 C D I magneto coupler 2 5 Crankcase breather hose 1 For installation reverse the removal pro cedure ENGINE 4 ...

Page 91: ...ing bolts Remove the parts in the order listed Carburetor Refer to CARBURETOR in chapter 5 Starter motor Refer to ELECTRIC STARTING SYS TEM in chapter 8 C D I magneto cover Refer to C D I MAGNETO 1 Metal clamp 2 2 Lower engine mounting nut bolt 1 1 CAUTION _ Install all of the bolts nuts and then tighten them to full torque specifica tions Refer to INSTALLING THE ENGINE ...

Page 92: ...Nm 3 3 m kg 24 ft Ib Order Job Part Q ty Remarks 3 Upper engine mounting nut bolt 1 1 Refer to INSTALLING THE ENGINE 4 Engine assembly 1 5 Dust boot 1 Refer to REMOVING THE ENGINE and INSTALLING THE ENGINE For installation reverse the removal pro cedure ENGINE ...

Page 93: ...stall dust boot 1 NOTE Before mounting the engine assembly install the dust boot onto the middle driven gear bear ing housing 1 2 Install upper engine mounting bolt nut 1 lower engine mounting bolt nut 2 NOTE _ Do not fully tighten the bolts and nuts 3 Tighten upper engine mounting nut 1 lower engine mounting nut 2 1 2 T R 33 Nm 3 3 m kg 24 ft lb T R 33 Nm 3 3 m kg 24 ft lb ...

Page 94: ...pipe muffler Refer to ENGINE C D I magneto cover Refer to C D I MAGNETO 1 Spark plug lead 1 2 Spark plug 1 3 Camshaft sprocket cover 1 4 Intake tappet cover 1 5 Exhaust tappet cover 1 6 Timing chain tension adjuster 1 Refer to REMOVING THE CYLINDER HEAD and INSTALLING THE CYLIN DER HEAD 7 Timing chain tensioner assembly 1 8 Camshaft sprocket 1 9 Cylinder head 1 10 Intake side timing chain guide 1 ...

Page 95: ...4 6 ENG Order Job Part Q ty Remarks 11 Exhaust side timing chain guide 1 12 Cylinder head gasket 1 13 Dowel pin 2 For installation reverse the removal pro cedure CYLINDER HEAD ...

Page 96: ...e when the camshaft sprocket alignment mark 3 is aligned with the cylinder head alignment mark 4 If not give the crankshaft one counterclock wise turn to meet the above condition 2 Loosen camshaft sprocket bolt 1 Use the sheave holder 2 to hold the rotor NOTE Do not allow the sheave holder to touch the projection on the rotor 3 Remove timing chain tension adjuster timing chain tensioner assembly c...

Page 97: ...ng chain as a set 1 1 4 of a tooth 2 Correct 3 Roller 4 Sprocket CHECKING THE TAPPET COVERS AND CAMSHAFT SPROCKET COVER 1 Check tappet covers 1 camshaft sprocket cover 2 O rings Cracks damage Replace 2 1 EBS00226 CHECKING THE TIMING CHAIN GUIDES 1 Check intake side timing chain guide 1 exhaust side timing chain guide 2 Wear damage Replace EBS00228 CHECKING THE TIMING CHAIN TENSIONER ASSEMBLY 1 Che...

Page 98: ...ral deposits rust Eliminate 3 Measure cylinder head warpage Out of specification Resurface the cylin der head a Place a straightedge and a thickness gauge across the cylinder head b Measure the warpage c If the limit is exceeded resurface the cylin der head as follows d Place a 400 600 grit wet sandpaper on the surface plate and resurface the cylinder head using a figure eight sanding pattern NOTE...

Page 99: ... is at the Top Dead Center TDC CAUTION _ Do not turn the crankshaft during the cam shaft sprocket installation d Place the timing chain onto the camshaft sprocket e Install the camshaft sprocket onto the cam shaft and finger tighten the sprocket bolt NOTE _ Be sure to align the alignment mark 5 on the camshaft sprocket with the alignment mark 2 on the cylinder head f Force the camshaft clockwise a...

Page 100: ...tion 2 The flat surface 3 of the timing chain ten sioner rod should face towards the adjuster threaded hole 4 WARNING _ Always use a new gasket 4 Adjust timing chain tensioner Refer to ADJUSTING THE TIMING CHAIN TENSIONER in chapter 3 T R 18 Nm 1 8 m kg 13 ft lb 3 4 1 2 5 Tighten camshaft sprocket bolt 1 NOTE _ Use the sheave holder 2 to hold the rotor Do not allow the sheave holder to touch the p...

Page 101: ...YLINDER HEAD 1 Intake manifold 1 2 Rocker arm shaft 2 Refer to REMOVING THE ROCKER ARMS AND CAMSHAFT and INSTALLING THE CAMSHAFT AND ROCKER ARMS 3 Rocker arm 2 4 Adjuster 2 5 Camshaft 1 6 Valve cotter 4 Refer to REMOVING THE VALVES AND VALVE SPRINGS and INSTALL ING THE VALVES AND VALVE SPRINGS 7 Valve spring retainer 2 8 Valve spring 2 9 Intake valve 1 10 Exhaust valve 1 11 Valve stem seal 2 12 Va...

Page 102: ...4 13 ENG Order Job Part Q ty Remarks 13 Valve guide 2 For installation reverse the removal pro cedure CAMSHAFT ROCKER ARMS AND VALVES ...

Page 103: ...rew a M8 bolt 2 into the threaded end of the camshaft and then pull out the camshaft Slide hammer set P N YU 01083 A Slide hammer bolt M8 P N 90890 01085 Weight P N 90890 01084 2 1 EBS00238 REMOVING THE VALVES AND VALVE SPRINGS 1 Check valve sealing Leakage at the valve seat Check the valve face valve seat and valve seat width Refer to CHECKING THE VALVES AND VALVE SPRINGS a Pour a clean solvent 1...

Page 104: ...nt P N YM 04108 90890 04108 2 1 EBS00223 CHECKING THE CAMSHAFT 1 Check cam lobes Pitting scratches blue discoloration Replace 2 Measure cam lobe dimensions a and b Out of specification Replace Camshaft lobe limit Intake a 25 200 mm 0 9921 in b 20 894 mm 0 8226 in Exhaust a 25 201 mm 0 9922 in b 20 921 mm 0 8237 in EBS00239 CHECKING THE ROCKER ARMS AND ROCKER ARM SHAFTS The following procedure appl...

Page 105: ...iameter 10 000 10 015 mm 0 3937 0 3943 in 5 Measure rocker arm shaft outside diameter a Out of specification Replace 6 Calculate rocker arm to rocker arm shaft clearance NOTE _ Calculate the clearance by subtracting the rocker arm shaft outside diameter from the rocker arm inside diameter Above 0 08 mm 0 0031 in Replace the defective part s Rocker arm shaft outside diame ter 9 981 9 991 mm 0 3930 ...

Page 106: ...alve guide remover 1 and valve guide installer 2 c After installing the valve guide bore the valve guide using a valve guide reamer 3 to obtain proper stem to guide clearance NOTE _ After replacing the valve guide reface the valve seat Stem to guide clearance valve guide inside diameter a valve stem diameter b Stem to guide clearance Intake 0 010 0 037 mm 0 0004 0 0015 in Limit 0 08 mm 0 0031 in E...

Page 107: ... Intake 0 5 0 9 mm 0 0197 0 0354 in Limit 1 6 mm 0 0630 in Exhaust 0 6 1 0 mm 0 0236 0 0394 in Limit 1 6 mm 0 0630 in 5 Measure runout valve stem Out of specification Replace NOTE _ When installing a new valve always replace the guide If the valve is removed or replaced always replace the oil seal 6 Eliminate carbon deposits from the valve face and valve seat 7 Check valve seats Pitting wear Refac...

Page 108: ...ce made contact blueing will have been removed e If the valve seat is too wide too narrow or the seat is not centered the valve seat must be refaced Valve seat width Intake 0 9 1 1 mm 0 0354 0 0433 in Limit 1 6 mm 0 063 in Exhaust 0 9 1 1 mm 0 0354 0 0433 in Limit 1 6 mm 0 063 in 9 Lap valve face valve seat NOTE _ After refacing the valve seat or replacing the valve and valve guide the valve seat ...

Page 109: ...e sure to clean off all of the compound from the valve face and valve seat f Apply Mechanic s blueing dye Dykem to the valve face g Install the valve into the cylinder head h Press the valve through the valve guide and onto the valve seat to make a clear pattern i Measure the valve seat width again If the valve seat width is out of specification reface and relap the valve seat 10 Measure valve spr...

Page 110: ...spring retainers NOTE _ Install the valve springs with the larger pitch a facing upwards b Smaller pitch 3 Install valve cotters NOTE _ Install the valve cotters while compressing the valve spring with the valve spring compressor 1 and attachment 2 4 To secure the valve cotters onto the valve stem lightly tap the valve tip with a piece of wood CAUTION _ Hitting the valve tip with excessive force c...

Page 111: ...G THE CAMSHAFT AND ROCKER ARMS 1 Install camshaft 1 NOTE _ Install the camshaft groove a facing down 2 Apply engine oil onto the rocker arm shafts 3 Install rocker arms 1 rocker arm shafts NOTE _ Use a slide hammer bolt 2 to install the rocker arm shaft 1 a 1 2 ...

Page 112: ...emove the parts in the order listed Cylinder head Refer to CYLINDER HEAD 1 Cylinder 1 Refer to INSTALLING THE CYLINDER 2 Cylinder gasket 1 3 Dowel pin 2 4 Piston pin clip 2 Refer to REMOVING THE PISTON and INSTALLING THE PISTON 5 Piston pin 1 6 Piston 1 7 Piston ring set 1 For installation reverse the removal pro cedure ...

Page 113: ...s NOTE _ Spread the end gaps apart while at the same time lifting the piston ring over the top of the piston crown Piston pin puller set P N YU 01304 90890 01304 3 2 1 EBS00249 CHECKING THE CYLINDER AND PISTON 1 Check piston wall cylinder wall Vertical scratches Rebore or replace the cylinder and replace the piston and piston rings as a set 2 Measure piston to cylinder clearance a Measure cylinder...

Page 114: ... the following formula f If out of specification rebore or replace the cylinder and replace the piston and piston rings as a set Cylinder bore C 39 000 39 005 mm 1 5354 1 5356 in Taper limit T 0 05 mm 0 002 in Out of round R 0 01 mm 0 0004 in C maximum of D1 D2 T maximum of D1 or D2 maximum of D5 or D6 R maximum of D1 D3 or D5 minimum of D2 D4 or D6 Piston size P Standard 38 960 38 975 mm 1 5339 1...

Page 115: ...inder with the piston crown 3 Measure piston ring end gap Out of specification Replace the piston ring NOTE _ The oil ring expander spacer s end gap cannot be measured If the oil ring rail s gap is exces sive replace all three piston rings Piston ring side clearance Top ring 0 030 0 065 mm 0 0012 0 0026 in Limit 0 12 mm 0 0047 in 2nd ring 0 020 0 055 mm 0 0008 0 0022 in Limit 0 12 mm 0 0047 in Pis...

Page 116: ...17 0 5118 in Limit 12 976 mm 0 5109 in 3 Measure piston pin bore diameter b Out of specification Replace the piston 4 Calculate piston pin to piston pin bore clearance Out of specification Replace the piston pin and piston as a set Piston pin bore diameter 13 002 13 013 mm 0 5119 0 5123 in Limit 13 043 mm 0 5135 in Piston pin to piston pin bore clearance Piston pin bore diameter b Piston pin outsi...

Page 117: ... ring end b Upper oil ring rail end c Expander end d Lower oil ring rail end e 2nd ring end f 20 mm 0 79 in 3 Install piston 1 piston pin 2 piston pin clips 3 NOTE _ Apply engine oil onto the piston pin piston rings and piston Be sure that the arrow mark a on the piston points to the exhaust side of the engine Before installing the piston pin clips cover the crankcase with a clean rag to prevent t...

Page 118: ...inder NOTE _ Install the cylinder with one hand while com pressing the piston rings with the other hand CAUTION _ Be careful not to damage the timing chain damper during installation Pass the timing chain through the timing chain cavity CYLINDER AND PISTON ...

Page 119: ...S AND FUEL TANK in chapter 3 1 Shift lever 1 Refer to INSTALLING THE SHIFT LEVER 2 C D I magneto cover 1 3 C D I magneto cover gasket 1 4 Dowel pin 2 5 C D I magneto rotor 1 Refer to REMOVING THE C D I MAG NETO ROTOR and INSTALLING THE C D I MAGNETO ROTOR 6 Woodruff key 1 7 Pickup coil stator assembly 1 8 Neutral switch 1 For installation reverse the removal pro cedure ...

Page 120: ...e holder 2 loosen the rotor nut Do not allow the sheave holder to touch the projection on the rotor Sheave holder P N YS 01880 A 90890 01701 1 2 2 Remove C D I magneto rotor 1 woodruff key NOTE _ Use the flywheel puller 2 Flywheel puller P N YM 01189 90890 01189 1 2 EBS00262 CHECKING THE PICKUP COIL STATOR ASSEMBLY 1 Check pickup coil stator assembly Damage Replace ...

Page 121: ...l the key and rotor 2 Tighten C D I magneto rotor nut NOTE _ While holding the C D I magneto rotor 1 with the sheave holder 2 tighten the C D I magneto rotor nut Do not allow the sheave holder to touch the projection on the rotor Sheave holder P N YS 01880 A 90890 01701 1 2 T R 40 Nm 4 0 m kg 29 ft lb INSTALLING THE SHIFT LEVER 1 Install shift lever NOTE Temporarily install the left footrest board...

Page 122: ...Refer to CHANGING THE ENGINE OIL in chapter 3 C D I magneto cover Refer to C D I MAGNETO 1 Clutch cover 1 Refer to REMOVING THE CLUTCH and INSTALLING THE CLUTCH 2 Clutch cover gasket 1 3 Dowel pin 2 4 Push plate 1 5 Circlip 1 6 Pressure plate 1 7 Push rod 1 8 Friction plate 1 with black color mark ing 4 Refer to INSTALLING THE CLUTCH ...

Page 123: ...te 2 1 12 Thrust weight plate 1 13 Clutch ball 12 14 Thrust plate 1 15 Clutch boss 1 16 Clutch boss one way cam 1 17 Primary driven gear clutch housing 1 18 Spacer 1 19 Primary drive gear 1 Refer to REMOVING THE PRIMARY DRIVE GEAR and INSTALLING THE PRIMARY DRIVE GEAR For installation reverse the removal pro cedure CLUTCH ...

Page 124: ...ING THE PRIMARY DRIVE GEAR 1 Loosen primary drive gear nut 1 NOTE _ Place an aluminum plate 2 between the teeth of the primary driven gear clutch housing 3 and primary drive gear 4 1 4 2 3 EBS00300 CHECKING THE FRICTION PLATES The following procedure applies to all of the friction plates 1 Check friction plate Damage wear Replace the friction plates as a set 2 Measure friction plate thickness Out ...

Page 125: ...LUTCH SPRINGS The following procedure applies to all of the clutch springs 1 Check clutch spring Damage Replace the clutch springs as a set 2 Measure clutch spring free length a Out of specification Replace the clutch springs as a set EBS00303 CHECKING THE CLUTCH HOUSING 1 Check clutch housing dogs Damage pitting wear Deburr the clutch housing dogs or replace the clutch housing clutch housing bear...

Page 126: ...atic clutch operation EBS00305 CHECKING THE PRESSURE PLATE 1 Check pressure plate Cracks damage Replace CHECKING THE CLUTCH BALLS 1 Check clutch ball Pitting damage wear Replace the clutch balls as a set EBS00307 CHECKING THE PRIMARY DRIVE GEARS 1 Check primary drive gear 1 primary driven gear 2 Damage wear Replace the primary drive gear and clutch housing as a set Excessive noise during operation...

Page 127: ...ve holder P N YS 01880 A 90890 01701 1 4 2 3 T R 50 Nm 5 0 m kg 36 ft lb INSTALLING THE CLUTCH 1 Install clutch balls NOTE Install the clutch balls 1 on the primary driven gear clutch housing as shown 1 1 1 1 2 Install thrust weight plate clutch boss one way cam clutch boss NOTE Align section a of the clutch boss one way cam with section b of the clutch boss and then install the primary driven gea...

Page 128: ...riction plate 1 4 Adjust friction plate height a Push the friction plate 1 1 down by hand b Measure the friction plate height a dis tance between the primary driven gear clutch housing 2 and friction plate 11 c If the height is out of specification adjust the friction plate height d Remove the clutch plate 1 friction plates 1 clutch plates 2 and friction plate 2 e Select the suitable clutch plates...

Page 129: ...lutch boss one way cam with section b of the clutch boss and then install the primary driven gear clutch housing b a 1 2 7 Tighten clutch boss nut 1 NOTE _ While holding the clutch boss 2 with the clutch holder 3 tighten the clutch boss nut 8 Install clutch balls NOTE Install the clutch balls on the primary driven gear clutch housing as shown Clutch holder P N 90890 04100 1 2 3 T R 60 Nm 6 0 m kg ...

Page 130: ... plates alter nately on the clutch boss starting and ending with a friction plate CAUTION The friction plate 2 2 must be placed between the thrust weight plate and the third clutch plate 2 The clutch plate 1 5 must be placed between the first and second friction plate 1 10 Install clutch cover NOTE _ Tighten the screws in stage using a crisscross pattern 4 4 2 1 3 5 6 a T R 7 Nm 0 7 m kg 5 1 ft lb...

Page 131: ... and oil pump Remove the parts in the order listed Clutch assembly Refer to CLUTCH 1 Starter idle gear assembly 1 2 Starter wheel gear 1 3 Starter clutch assembly 1 4 Spacer 1 5 Oil pump drive gear 1 6 Oil pump driven gear 1 7 Oil pump assembly 1 8 Oil pump gasket 1 9 Oil strainer 1 For installation reverse the removal pro cedure ...

Page 132: ... 5 4 3 2 1 Order Job Part Q ty Remarks Disassembling the oil pump Remove the parts in the order listed 1 Oil pump housing cover 1 2 Oil pump shaft 1 3 Inner rotor 1 4 Outer rotor 1 5 Oil pump housing 1 For assembly reverse the disassembly procedure ...

Page 133: ... a center punch T R Starter clutch screw 10 Nm 1 0 m kg 7 2 ft lb LOCTITE 3 Check starter clutch operation a Install the starter wheel gear to the starter clutch and hold the starter clutch b When turning the starter wheel gear clock wise È the starter clutch and the wheel gear should be engaged If not the starter clutch is faulty Replace it c When turning the starter wheel gear coun terclockwise ...

Page 134: ... clips roughness wear Replace 5 Check starter wheel gear contacting surface a Damage pitting wear Replace a 2 1 EBS00330 CHECKING THE OIL PUMP 1 Check oil pump drive gear 1 oil pump driven gear 2 oil pump housing 3 oil pump housing cover 4 Cracks wear damage Replace 2 Clean oil strainer 1 Damage Replace ...

Page 135: ...nner rotor 2 Outer rotor 3 Oil pump housing Inner rotor to outer rotor tip clearance 0 05 0 07 mm 0 002 0 003 in Limit 0 15 mm 0 006 in Outer rotor to oil pump housing clearance 0 013 0 036 mm 0 0005 0 0014 in Limit 0 106 mm 0 0042 in Oil pump housing to inner rotor and outer rotor clearance 0 06 0 10 mm 0 0024 0 0039 in Limit 0 17 mm 0 0067 in 4 Check oil pump operation Rough movement Repeat step...

Page 136: ...er Job Part Q ty Remarks Removing the shift shaft Remove the parts in the order listed Clutch assembly Refer to CLUTCH 1 Shift shaft 1 2 Stopper lever 1 3 Dowel pin 5 For installation reverse the removal pro cedure SHIFT SHAFT ...

Page 137: ... stopper lever INSTALLING THE STOPPER LEVER 1 Install stopper lever 1 NOTE Hook the hooked end of the stopper lever spring onto the stopper lever and catch the straight end of the stopper lever spring onto the crankcase 1 INSTALLING THE SHIFT SHAFT 1 Install shift shaft 1 NOTE Install the end of the shift shaft spring onto the shift shaft spring stopper 2 Make sure that the arm section of the shif...

Page 138: ...EAD Cylinder and piston Refer to CYLINDER AND PISTON C D I magneto Refer to C D I MAGNETO Clutch Refer to CLUTCH Starter clutch and oil pump Refer to STARTER CLUTCH AND OIL PUMP Shift shaft Refer to SHIFT SHAFT 1 Timing chain 1 2 Shift drum retainer 1 3 Right crankcase 1 Refer to SEPARATING THE CRANK CASE and ASSEMBLING THE CRANKCASE 4 Dowel pin 2 5 Left crankcase 1 For installation reverse the re...

Page 139: ...art Q ty Remarks Removing the crankcase bearings Remove the parts in the order listed Crankshaft Refer to CRANKSHAFT Transmission Refer to TRANSMISSION Middle driven pinion gear Refer to MIDDLE GEAR 1 Bearing retainer 1 2 Bearing 6 Refer to INSTALLING THE BEARINGS For installation reverse the removal pro cedure ...

Page 140: ...NOTE _ Insert a screwdriver or pry bar into the pry points in the crankcase and then carefully pry apart the crankcase halves CAUTION _ Use a soft hammer to tap on one side of the crankcase Tap only on reinforced portions of the crankcase Do not tap on the crank case mating surfaces Work slowly and carefully Make sure that the crankcase halves separate evenly c Remove the dowel pins EBS00335 CHECK...

Page 141: ...ughly wash the case halves in a mild solvent 2 Clean all the gasket mating surfaces and crankcase mating surfaces thoroughly 3 Check crankcase Cracks damage Replace oil delivery passages Clogged Blow out with compressed air INSTALLING THE BEARINGS 1 Install left main axle bearing 1 NOTE Press the left main axle bearing into the left crankcase 2 as shown in the illustration a 34 0 34 5 mm 1 34 1 36...

Page 142: ...her the transmission is functioning properly by manually rotating the shift drum in both directions 4 Install gaskets 1 crankcase screws 5 Tighten crankcase screws 2 Screw 45 mm 3 Screw 60 mm 4 Screw 75 mm NOTE _ Tighten the screws in stages using a criss cross pattern 6 Apply 4 stroke engine oil to the crankshaft pin bearing and oil deliv ery hole 7 Check crankshaft and transmission operation Uns...

Page 143: ...er Job Part Q ty Remarks Removing the crankshaft Remove the parts in the order listed Crankcase Separate Refer to CRANKCASE 1 Crankshaft 1 Refer to INSTALLING THE CRANK SHAFT For installation reverse the removal pro cedure CRANKSHAFT ...

Page 144: ...he big end bearing crankshaft pin connecting rod and or side washer as a set Crank width 40 20 40 25 mm 1 5827 1 5846 in Big end side clearance 0 10 0 40 mm 0 0039 0 0157 in Limit 0 50 mm 0 0197 in Runout limit C1 0 05 mm 0 0020 in C2 0 04 mm 0 0016 in Small end free play Standard 0 80 1 00 mm 0 0315 0 0394 in Limit 1 50 mm 0 0591 in f a d C1 C2 EBS00362 INSTALLING THE CRANKSHAFT 1 Install cranksh...

Page 145: ...eparate Refer to CRANKCASE 1 Main axle 1st pinion gear 1 2 Shift fork guide bar 1 Refer to REMOVING THE TRANSMIS SION and INSTALLING THE TRANS MISSION 3 Shift fork 1 4 Drive axle middle drive pinion gear assembly 1 5 Shift drum 1 6 1st wheel gear 1 7 Drive axle dog gear 1 8 Middle drive gear shim 1 For installation reverse the removal pro cedure ...

Page 146: ...case together 4 1 2 3 EBS00350 CHECKING THE SHIFT FORK 1 Check shift fork cam follower 1 shift fork pawl 2 Bends damage scoring wear Replace the shift fork 2 Check shift fork guide bar Roll the shift fork guide bar on a flat surface Bends Replace WARNING _ Do not attempt to straighten a bent shift fork guide bar 3 Check shift fork movement along the shift fork guide bar Rough movement Replace the ...

Page 147: ... 2 Measure drive axle runout with a centering device and dial gauge 1 Out of specification Replace the drive axle 3 Check transmission gears Blue discoloration pitting wear Replace the defective gear s transmission gear dogs Cracks damage rounded edges Replace the defective gear s 4 Check transmission gear engagement each pinion gear to its respective wheel gear Incorrect Reassemble the transmissi...

Page 148: ...t fork should face towards the left of the engine Be sure to install the forked section a of the drive axle middle drive gear assembly around the shift fork guide bar when install ing the transmission 2 4 3 1 a 2 Check transmission Rough movement Repair NOTE _ Oil each gear and bearing thoroughly Before assembling the crankcase be sure that the transmission is in neutral and that the gears turn fr...

Page 149: ...ar assembly Refer to TRANSMISSION 1 Middle drive gear shim 1 2 Middle driven gear shim Refer to SELECTING MIDDLE DRIVEN GEAR SHIMS 3 Bearing 4 Refer to REMOVING THE MIDDLE DRIVEN SHAFT and INSTALLING THE MIDDLE DRIVEN SHAFT 4 Universal joint 1 5 Universal joint yoke 2 6 Middle driven shaft with driven pinion gear 1 7 Bearing retainer 1 8 Bearing housing 1 For installation reverse the removal pro c...

Page 150: ...own NOTE _ It may be necessary to lightly tap the yoke with a punch d Repeat the steps for the opposite bearing e Remove the yoke NOTE _ It may be necessary to lightly tap the yoke with a punch 2 Remove nut 1 washer universal joint yoke front side NOTE _ Use the universal joint holder 2 and attach ment 3 to hold the universal joint yoke Universal joint holder P N YM 04062 90890 04062 Universal joi...

Page 151: ...e socket 2 on the shaft end to protect the thread from damage c Press the shaft end and remove the bearing housing 4 Remove bearing retainer bearing a Place a folded rag 1 b Secure the bearing housing edge in the vise c Attach the damper rod holder 2 d Remove the bearing retainer and bearing 27 mm hexagon wrench P N YM 01363 Damper rod holder 27 mm P N 90890 01388 1 2 EBS01021 CHECKING THE PINION ...

Page 152: ...ddle driven gear shim 1 a Measure the distance a between the mid dle driven shaft bearing housing and the middle driven pinion gear b Determine the difference using the following chart c Select the suitable shim s according to the following chart a mm Difference mm 37 83 a 37 90 0 4 37 90 a 38 00 0 5 38 00 a 38 10 0 6 38 10 a 38 20 0 7 38 20 a 38 30 0 8 38 30 a 38 40 0 9 38 40 a 38 45 1 0 Differen...

Page 153: ...eads with a drift punch 27 mm hexagon wrench P N YM 01363 Damper rod holder 27 mm P N 90890 01388 T R Bearing retainer 60 Nm 6 0 m kg 43 ft lb LOCTITE New 1 2 2 Install universal joint yoke front side washer nut 1 NOTE _ Use the universal joint holder 2 and attach ment 3 to hold the yoke Apply locking agent LOCTITE to the nut threads Lock the threads with a drift punch Universal joint holder P N Y...

Page 154: ...g The needles can eas ily fall out of their races Slide the yoke back and forth on the bearings the yoke will not go all the way onto a bearing if a needle is out of place d Press each bearing into the universal joint using a suitable socket NOTE _ The bearing must be inserted far enough into the universal joint so that the circlip can be installed e Install the circlips into the groove of each yo...

Page 155: ... clamp as shown to secure the pinion gear fix clamp c Attach the gear lash measurement tool 2 and dial gauge 3 a 25 2 mm 0 99 in d Measure the gear lash while rotating the middle driven shaft back and forth NOTE _ Measure the gear lash at 4 positions Rotate the middle driven gear 90 each time e If the gear lash is incorrect adjust the gear lash by middle driven gear shim s Middle gear lash 0 17 0 ...

Page 156: ...he carburetor Remove the parts in the order listed 1 Fuel overflow hose 1 2 Carburetor air vent hose 1 3 Fuel hose 1 4 Carburetor assembly 1 5 Carburetor top cover 1 6 Throttle cable 1 Refer to INSTALLING THE CARBURE TOR 7 Spring 1 8 Piston valve 1 9 Jet needle set 1 For installation reverse the removal pro cedure CARBURETOR 5 ...

Page 157: ...emove the parts in the order listed NOTE _ Before disassembling the carburetor make sure to note the number of times the pilot screw is turned out from the seated position to its set position 1 Throttle stop screw 1 2 Float chamber 1 3 Pilot jet 1 4 Main jet 1 5 Needle jet 1 6 Float pin 1 ...

Page 158: ...5 3 CARB Order Job Part Q ty Remarks 7 Float 1 Refer to ASSEMBLING THE CARBURE TOR 8 Needle valve 1 For assembly reverse the disassembly procedure CARBURETOR ...

Page 159: ...CKING THE CARBURETOR 1 Check carburetor body float chamber Cracks damage Replace fuel passage Contamination Clean as indicated fuel chamber body Contamination Clean a Wash the carburetor in a petroleum based solvent Do not use any caustic carburetor cleaning solution b Blow out all of the passages and jets with compressed air 2 Check float 1 float tang 2 Damage Replace 3 Check needle valve 1 Conta...

Page 160: ... 6 Check jet needle 1 main jet 2 needle jet 3 pilot jet 4 throttle stop screw 5 Bends wear damage Replace Blockage Blow out the jets with com pressed air 7 Check piston valve movement Sticks Replace the piston valve Insert the piston valve into the carburetor body and check for free movement 8 Check choke valve movement Sticks Replace ...

Page 161: ...times as noted before disassembly from the seated position to the set position CAUTION _ Before reassembling wash all of the parts in a clean petroleum based solvent Always use a new gasket INSTALLING THE CARBURETOR 1 Install jet needle set piston valve spring throttle cable NOTE Align the slit 1 of the throttle valve with the tab 2 of the carburetor body ...

Page 162: ...he float chamber e Measure the fuel level Fuel level below the float chamber mating surface 4 0 5 0 mm 0 16 0 20 in Fuel level gauge P N YM 01312 A 90890 01312 2 Adjust fuel level a Remove the carburetor assembly b Check the needle valve seat and needle valve c If either is worn replace them as a set d If both are fine adjust the float level by slightly bending the float tang 1 e Install the carbu...

Page 163: ... pronounced hesitation or jerky move ment during acceleration deceleration or sustained speed This must not be con fused with engine surging or transmission characteristics 2 A rolling rumble noticeable at low speed a high pitched whine a clunk from a shaft drive component or area 3 A locked up condition of the shaft drive train mechanism no power transmitted from the engine to the rear wheels A B...

Page 164: ...remely destructive to the gear teeth If a test ride following reassembly indicates this condition stop riding immediately to minimize gear dam age c A slight thunk evident at low speed opera tion This noise must be distinguished from normal machine operation Diagnosis Possible broken gear teeth WARNING _ Stop riding immediately if broken gear teeth are suspected This condition could result in the ...

Page 165: ...est the machine for the distance nec essary to locate the leak Leakage Check the component housing gasket and or seal for damage Damage Replace the component NOTE _ An apparent oil leak on a new or nearly new machine may be the result of a rust preven tative coating or excessive seal lubrication Always clean the machine and recheck the suspected location of an apparent leakage ...

Page 166: ...brake adjustment NO Adjust per instructions Refer to ADJUSTING THE REAR BRAKE in chapter 3 YES Check the rear axle Feel for bearing dam age NO Rear axle bearings and rear drive shaft bearings are probably not damaged Repeat the test or remove the individual compo nents YES Remove the rear axle Check for axle bear ing damage YES Replace the rear axle bearing Refer to REAR AXLE FINAL DRIVE ASSEMBLY ...

Page 167: ...mbly and drive shaft Remove the parts in the order listed Rear wheels Refer to FRONT AND REAR WHEELS in chapter 7 Brake drum cover Refer to FRONT AND REAR BRAKES in chapter 7 Final gear oil Drain Refer to CHANGING THE FINAL GEAR OIL in chapter 3 1 Nut 1 Refer to REMOVING THE NUTS and INSTALLING THE NUTS 2 Nut 1 3 Final gear case breather hose 1 4 Bolt nut 1 1 5 Swingarm guard 1 ...

Page 168: ...nal drive assembly 1 Refer to REMOVING THE REAR AXLE FINAL DRIVE ASSEMBLY and INSTALLING THE REAR AXLE FINAL DRIVE ASSEMBLY 7 Drive shaft 1 8 Coupling gear 1 For installation reverse the removal pro cedure REAR AXLE FINAL DRIVE ASSEMBLY AND DRIVE SHAFT ...

Page 169: ...Rear axle housing 1 2 Rear axle housing bearing retainer 1 Refer to DISASSEMBLING THE REAR AXLE HOUSING and ASSEMBLING THE REAR AXLE HOUSING 3 Spacer 1 4 Final gear case bearing retainer 1 Refer to DISASSEMBLING THE FINAL GEAR CASE and ASSEMBLING THE FINAL GEAR CASE 5 Spacer 1 6 Final drive pinion gear 1 7 Rear axle with final drive ring gear 1 8 Final gear case 1 For assembly reverse the disassem...

Page 170: ... by placing the suit able stand under the frame 4 Remove rear wheels wheel hubs nuts 5 Remove rear brake assembly Refer to FRONT AND REAR BRAKES in chapter 7 Axle nut wrench 36 mm P N YM 37132 90890 01422 REMOVING THE REAR AXLE FINAL DRIVE ASSEMBLY 1 Remove rear axle final drive assembly 1 NOTE Remove the rear axle final drive assembly as an assembly after removing each bolt and nut REAR AXLE FINA...

Page 171: ...81 DISASSEMBLING THE FINAL GEAR CASE 1 Remove rear axle with final drive ring gear CAUTION _ Never directly tap the axle end with a ham mer since this will result in damage to the axle thread and spline 2 Remove final gear case bearing retainer NOTE _ Use a ring nut wrench 1 3 Remove final drive pinion gear assembly With a soft hammer lightly tap on the final drive pinion gear end Ring nut wrench ...

Page 172: ...mit 1 5 mm 0 06 in EBS00191 CHECKING THE DRIVE SHAFT 1 Check drive shaft splines 1 coupling gear splines 2 Wear damage Replace EBS00192 CHECKING THE REAR AXLE HOUSING AND FINAL DRIVE ASSEMBLY 1 Check final gear case 1 rear axle housing 2 Cracks damage Replace 2 Check gear teeth Pitting galling wear Replace the drive pinion gear and ring gear as a set oil seals O rings Damage Replace 3 Check bearin...

Page 173: ...nstall the oil seal and dust seal as shown a 6 6 5 mm 0 24 0 26 in b 1 2 mm 0 04 0 08 in Ring nut wrench P N YM 38404 90890 01430 T R 80 Nm 8 0 m kg 58 ft lb EBS00195 ASSEMBLING THE REAR AXLE HOUSING 1 Install rear axle housing bearing retainer Use a bearing retainer wrench 1 CAUTION _ Always use a new bearing 2 Install bearing 1 NOTE Install the bearing as shown a 0 5 mm 0 02 in 2 rear axle housi...

Page 174: ... mating surfaces of the swingarm and the final gear case b Temporarily install the rear axle final drive assembly 1 on the swingarm 2 The bolts and nuts should be temporarily tightened c Check that the rear axle rotates smoothly d Tighten the bolts and nuts 1 Rear axle final drive assembly 2 Swingarm 3 Bolt 4 4 Nut 3 5 Bolt 6 Lithium soap based grease Sealant Quick Gasket P N ACC 11001 05 01 Yamah...

Page 175: ...ighten the inside nut with rear axle nut wrench to specification while holding the rear axle d Hold the inside nut 1 and tighten the out side nut 2 with the rear axle nut wrench to specification e Draw a line a on the inside and outside nut f Hold the outside nut 2 and tighten back the inside nut 1 with the rear axle nut wrench to specification g Measure the distance b between the lines If distanc...

Page 176: ...hine on a level surface WARNING _ Securely support the machine so there is no danger of it falling over The following procedure applies to both of the front wheels 1 Cotter pin 1 Refer to INSTALLING THE WHEEL HUBS 2 Axle nut 1 3 Front wheel 1 Refer to INSTALLING THE WHEELS 4 Front brake drum 1 For installation reverse the removal pro cedure FRONT AND REAR WHEELS 7 ...

Page 177: ...el surface WARNING _ Securely support the machine so there is no danger of it falling over The following procedure applies to both of the rear wheels 1 Cotter pin 1 Refer to INSTALLING THE WHEEL HUBS 2 Axle nut 1 3 Rear wheel 1 Refer to INSTALLING THE WHEELS 4 Rear wheel hub 1 For installation reverse the removal pro cedure FRONT AND REAR WHEELS ...

Page 178: ...to do so may cause an accident resulting in machine damage and possible operator injury Wheel runout limit Radial 2 2 0 mm 0 08 in Lateral 3 2 0 mm 0 08 in EBS00385 CHECKING THE FRONT WHEEL HUBS The following procedure applies to both of the front wheel hubs 1 Check front wheel hub 1 Cracks damage Replace 2 Check wheel bearings Wheel hub play wheel turns roughly Replace a Clean wheel hub exterior ...

Page 179: ...uter race EBS00384 CHECKING THE REAR WHEEL HUBS The following procedure applies to both of the rear wheel hubs 1 Check rear wheel hub 1 Cracks damage Replace wheel hub splines 2 Wear damage Replace EBS00390 INSTALLING THE WHEEL HUBS The following procedure applies to both of the front and rear wheel hubs 1 Install axle nut 1 cotter pin 2 NOTE _ Do not loosen the axle nut after torquing it If the a...

Page 180: ... WHEELS The following procedure applies to both of the front and rear wheels 1 Install wheel NOTE _ The arrow mark 1 on the tire must point in the direction of rotation of the wheel È Front wheel É Rear wheel 2 Tighten nuts È É T R 28 Nm 2 8 m kg 20 ft lb ...

Page 181: ...edure applies to both of the front brakes 1 Brake shoe 2 Refer to INSTALLING THE FRONT BRAKES 2 Front brake cable drum side 1 3 Brake shoe plate 1 4 Brake camshaft lever 1 Refer to REMOVING THE BRAKES and INSTALLING THE FRONT BRAKES 5 Brake shoe wear indicator 1 6 Brake camshaft 1 7 Left front brake cable lever side 1 8 Right front brake cable lever side 1 9 Front brake lever 1 For installation re...

Page 182: ...ake drum cover 1 2 Nut 1 Refer to REAR AXLE FINAL DRIVE ASSEMBLY AND DRIVE SHAFT in chapter 6 3 Nut 1 4 Lock washer 2 Refer to INSTALLING THE REAR BRAKE 5 Brake drum 1 6 Brake drum boss 1 7 Brake shoe 2 8 Rear brake cable drum side 1 9 Brake camshaft lever 1 Refer to REMOVING THE BRAKES and INSTALLING THE REAR BRAKE 10 Brake shoe wear indicator 1 11 Brake camshaft 1 ...

Page 183: ...7 8 CHAS Order Job Part Q ty Remarks 12 Rear brake cable lever side 1 13 Rear brake switch 1 14 Rear brake lever 1 For installation reverse the removal pro cedure FRONT AND REAR BRAKES ...

Page 184: ...d with the punch mark in the brake camshaft EBS00439 CHECKING THE BRAKE SHOE PLATES The following procedure applies to each brake 1 Check brake shoe plate pivot pin brake camshaft Bends cracks damage Replace dust seal Wear damage Replace EBS00440 CHECKING THE BRAKE SHOES The following procedure applies to each brake 1 Check brake shoes 1 brake shoe springs 2 Cracks damage Replace as a set NOTE _ W...

Page 185: ...nts NOTE _ Replace the brake shoes as a set if either is found to be worn to the wear limit Brake lining thickness 4 0 mm 0 16 in Limit 2 0 mm 0 08 in EBS00441 CHECKING THE BRAKE DRUMS The following procedure applies to each brake 1 Measure brake drum inside diameter a Out of specification Replace È Front brake drum É Rear brake drum Rear brake drum inside diameter Front 110 0 mm 4 33 in Limit 110...

Page 186: ...shaft and the pivot pin Wipe off the excess grease 2 Install brake camshaft 1 brake shoe wear indicator 2 brake camshaft lever NOTE _ Install the brake camshaft so its punch mark a is positioned as shown Align the projection on the brake shoe wear indicator with the notch in the brake cam shaft Align the punch mark in the brake camshaft with the mark on the brake camshaft lever È Left side É Right...

Page 187: ...ake shoes are properly posi tioned 5 Check brake camshaft operation Unsmooth operation Repair 6 Adjust front brake Refer to ADJUSTING THE FRONT BRAKE in chapter 3 EBS00442 INSTALLING THE REAR BRAKE Reverse the Removal procedure Note the following points 1 Lubricate brake camshaft pivot pin CAUTION _ During installation lightly grease the brake camshaft and the pivot pin Wipe off the excess grease ...

Page 188: ...h mark in the brake camshaft with the mark on the brake camshaft lever 3 Install rear brake cable drum side brake shoes NOTE Check that the brake shoes are properly posi tioned 4 Install brake drum boss brake drum lock washers 1 NOTE Bend the tabs of each lock washer along a flat side of each nut 5 Check brake camshaft operation Unsmooth operation Repair 6 Adjust rear brake Refer to ADJUSTING THE ...

Page 189: ...AT FENDERS AND FUEL TANK in chapter 3 1 Handlebar grip 2 Refer to REMOVING THE HANDLEBAR GRIPS and INSTALLING THE HAN DLEBAR GRIPS 2 Front brake cable 2 3 Front brake lever assembly 1 Refer to INSTALLING THE FRONT BRAKE LEVER ASSEMBLY 4 Handlebar switch 1 Refer to INSTALLING THE REAR BRAKE LEVER 5 Rear brake cable 1 6 Rear brake switch 1 7 Rear brake lever 1 8 Plastic band 1 ...

Page 190: ...15 CHAS Order Job Part Q ty Remarks 9 Upper handlebar holder 2 Refer to INSTALLING THE HANDLE BAR 10 Handlebar 1 11 Lower handlebar holder 1 For installation reverse the removal pro cedure STEERING SYSTEM ...

Page 191: ...sh the grip off the handlebar EBS00445 REMOVING THE REAR BRAKE SWITCH 1 Remove rear brake switch 1 NOTE _ Push the fastener when removing the rear brake switch out of the rear brake lever holder EBS00448 CHECKING THE HANDLEBAR 1 Check handlebar 1 Bends cracks damage Replace WARNING _ Do not attempt to straighten a bent handle bar as this may dangerously weaken the handlebar ...

Page 192: ... punched mark 1 forward 2 CAUTION _ First tighten the bolt 3 on the front side of the handlebar holder and then tighten the bolt 4 on the rear side T R 20 Nm 2 0 m kg 14 ft lb EBS00450 INSTALLING THE HANDLEBAR GRIPS 1 Install handlebar grips NOTE _ Before installing the handlebar grips tempo rarily install the rear brake lever and front brake lever assembly on the handlebar Before applying the adh...

Page 193: ... the positions shown in the illustration 2 Adjust rear brake Refer to ADJUSTING THE REAR BRAKE in chapter 3 EBS00452 INSTALLING THE FRONT BRAKE LEVER ASSEMBLY 1 Install front brake lever assembly 1 NOTE _ Install the front brake lever assembly within 10 from the horizontal line shown in the illustration After installing the front brake lever assem bly make sure that the clearance a between the fro...

Page 194: ...listed Front fender Refer to SEAT FENDERS AND FUEL TANK in chapter 3 Handlebar Refer to HANDLEBAR 1 Lock washer 1 Refer to INSTALLING THE LOCK WASHER 2 Steering stem bushing 2 3 Spacer 2 4 Oil seal 2 5 Steering stem 1 Refer to REMOVING THE STEERING STEM and INSTALLING THE STEER ING STEM For installation reverse the removal pro cedure ...

Page 195: ...tempt to straighten a bent stem this may dangerously weaken the stem 2 Check steering stem bushings 1 Wear damage Replace INSTALLING THE STEERING STEM 1 Tighten steering stem nut 1 tie rod end nut 2 NOTE When tightening each tie rod end nut 2 hold the tie rod ball joint with a 14 mm wrench 3 EBS00459 INSTALLING THE LOCK WASHER 1 Install lock washer 1 NOTE Bend a lock washer tab along a flat side o...

Page 196: ... Remove the parts in the order listed Front brakes Refer to FRONT AND REAR BRAKES The following procedure applies to both of the tie rods and steering knuckles 1 Tie rod 1 Refer to REMOVING THE TIE RODS and INSTALLING THE TIE RODS 2 Steering knuckle 1 3 Thrust cover 2 4 Spacer 1 5 Bushing 2 For installation reverse the removal pro cedure ...

Page 197: ... then loosen the tie rod end nut EBS00462 CHECKING THE TIE RODS The following procedure applies to both of the tie rods 1 Check tie rod free play and movement Free play Replace the tie rod end Turns roughly Replace the tie rod end 2 Check tie rod Bends damage Replace EBS00464 CHECKING THE STEERING KNUCKLES The following procedure applies to both of the steering knuckles 1 Check steering knuckle Da...

Page 198: ...all tie rod NOTE _ The tie rod side which must be installed on the inside has grooves 1 When installing the tie rod hold each tie rod ball joint with a 14 mm wrench 2 and then tighten the tie rod end nut 2 Adjust toe in Refer to ADJUSTING THE TOE IN in chapter 3 T R 15 Nm 1 5 m kg 11 ft lb STEERING SYSTEM ...

Page 199: ...T SWINGARM Order Job Part Q ty Remarks Removing the front shock absorber assemblies and front swingarm Remove the parts in the order listed Steering knuckles Refer to STEERING SYSTEM 1 Front shock absorber 2 2 Front swingarm 1 Refer to REMOVING THE FRONT SWINGARM For installation reverse the removal pro cedure ...

Page 200: ...d down If the vertical movement is tight or rough or if there is binding check the bushings 2 Remove front swingarm EBS00470 CHECKING THE FRONT SWINGARM 1 Check front swingarm 1 Bends damage Replace 2 Check bushings 2 Wear damage Replace EBS00471 CHECKING THE FRONT SHOCK ABSORBER ASSEMBLIES 1 Check shock absorber rod Bends damage Replace the shock absorber assembly shock absorber assembly Oil leak...

Page 201: ... order listed C D I magneto cover Refer to C D I MAGNETO in chapter 4 Rear axle final drive assembly Refer to REAR AXLE FINAL DRIVE ASSEMBLY AND DRIVE SHAFT in chapter 6 1 Rear shock absorber 1 2 Pivot shaft 1 3 Lock washer 1 Refer to INSTALLING THE LOCK WASHER 4 Rear swingarm 1 Refer to REMOVING THE REAR SWIN GARM 5 Metal clamp 2 6 Dust boot 1 For installation reverse the removal pro cedure ...

Page 202: ...eck the rear swingarm vertical movement É by moving it up and down If vertical movement is tight or rough or if there is binding check the bushings spacer and pivot shaft 2 Remove pivot shaft rear swingarm T R Pivot shaft 85 Nm 8 5 m kg 61 ft lb EBS00478 CHECKING THE REAR SHOCK ABSORBER 1 Check shock absorber Oil leaks Replace the shock absorber assembly shock absorber rod Bends damage Replace the...

Page 203: ...e Replace 2 Check bushings Wear damage Replace EBS00481 CHECKING THE DUST BOOT 1 Check dust boot 1 Damage Replace INSTALLING THE LOCK WASHER 1 Install lock washer 1 NOTE Insert the small tab of the lock washer in the groove on the swingarm and then bend the other lock washer tab along a flat side of the pivot shaft head New ...

Page 204: ...Rear brake switch 4 Handlebar switch 5 Battery 6 Main fuse 7 Engine stop switch frame 8 Rectifier regulator 9 Diode 0 Starting circuit cut off relay A Starter relay B Neutral switch C Pickup coil stator assembly D Starter motor E Ignition coil F C D I unit G Wire harness ELECTRICAL COMPONENTS 8 ...

Page 205: ...ty switch back and forth between the switch positions a few times The terminal connections for switches e g main switch engine stop switch are shown in an illustration similar to the one on the left The switch positions a are shown in the far left column and the switch lead colors b are shown in the top row in the switch illustration NOTE _ indicates a continuity of electricity between switch term...

Page 206: ... to CHECKING SWITCH CONTINUITY Damage wear Repair or replace Improperly connected Properly connect Incorrect continuity reading Replace the switch ON OFF B B B R R Br Br Br B W B W R W B W OFF ON RUN OFF Br B R W BLACK B B Sb BLACK B B 1 2 3 4 5 6 1 Main switch 2 Start switch 3 Engine stop switch handlebar 4 Rear brake switch 5 Neutral switch 6 Engine stop switch frame ...

Page 207: ...illustration on the left Bulbs a and b are used for the headlights and usually use a bulb holder that must be detached before removing the bulb The majority of these types of bulbs can be removed from their respective socket by turning them counterclockwise Bulbs c is used for turn signal and tail brake lights and can be removed from the socket by pushing and turning the bulb counterclockwise Bulb...

Page 208: ...lb and the luminous flux will be adversely affected If the headlight bulb gets soiled thoroughly clean it with a cloth moistened with alcohol or lacquer thinner 2 Check bulb for continuity with the pocket tester No continuity Replace NOTE _ Before checking for continuity set the pocket tester to 0 and to the Ω 1 range a Connect the positive tester probe to termi nal 1 and the negative tester probe...

Page 209: ...ntinuity Replace NOTE _ Check each bulb socket for continuity in the same manner as described in the bulb section however note the following a Install a good bulb into the bulb socket b Connect the pocket tester probes to the respective leads of the bulb socket c Check the bulb socket for continuity If any of the readings indicate no continuity replace the bulb socket Pocket tester P N YU 03112 C ...

Page 210: ...G W W L W R B R W Y R B Sb B Y R W Sb B Y R W B R Br B W B W B B B B W Br R B W R Y R B Br Br Sb Y R B W R B B W B R O R W L R W R R R R R B B B B 5A L W R W L W B L W R W B Y Sb L W L W R W Sb B Y G Y B Y Br B R W Br B R W B W B B Y G Y BLACK BLACK B B G Y B G Y B B B B R R 1 4 5 6 9 A E 7 8 3 K B C D 2 G F H I J 0 1 C D I magneto 3 Main switch B C D I unit C Ignition coil D Spark plug G Engine s...

Page 211: ...shoot with the following special tool s EBS01032 YES NO The ignition system fails to operate no spark or intermittent spark Dynamic spark tester P N YM 34487 Ignition checker P N 90890 06754 Pocket tester P N YU 03112 C 90890 03112 1 Spark plug Check the condition of the spark plug Check the spark plug type Measure the spark plug gap Refer to CHECKING THE SPARK PLUG in chapter 3 Standard spark plu...

Page 212: ...ushing the starter switch and gradually increase the spark gap until a misfire occurs Minimum ignition spark gap 6 mm 0 24 in Is there a spark and is the spark gap within specification The ignition system is OK 3 Spark plug cap resistance Remove the spark plug cap from the spark plug lead Connect the pocket tester Ω 1k range to the spark plug cap as shown Measure the spark plug cap resistance Spar...

Page 213: ...F Connect the pocket tester Ω 1k to the ignition coil as shown Positive tester probe orange terminal Negative tester probe spark plug lead Measure the secondary coil resistance Secondary coil resistance 6 32 9 48 kΩ at 20 C 68 F Is the ignition coil OK Replace the ignition coil 5 Main switch Check the main switch for continuity Refer to CHECKING THE SWITCHES Is the main switch OK Replace the main ...

Page 214: ...up coil stator assembly G W W L W R B R 1 2 8 Source coil resistance Disconnect the C D I magneto coupler from the wire harness Connect the pocket tester Ω 100 to the source coil terminal Positive tester probe black red terminal 1 Negative tester probe green white terminal 2 Measure the source coil resistance Source coil resistance 304 456 Ω at 20 C 68 F black red and green white Replace the picku...

Page 215: ... Y R W Sb B Y R W B R Br B W B W B B B B W Br R B W R Y R B Br Br Sb Y R B W R B B W B R O R W L R W R R R R R B B B B 5A L W R W L W B L W R W B Y Sb L W L W R W Sb B Y G Y B Y Br B R W Br B R W B W B B Y G Y BLACK BLACK B B G Y B G Y B B B B R R 1 4 5 6 9 A E 7 8 3 K B 2 G F H I J 0 2 Neutral switch 3 Main switch 5 Main fuse 6 Positive battery lead 7 Battery 8 Negative battery lead 9 Starter rel...

Page 216: ...d the engine stop switch is in the RUN position the starter motor can be operated only if 1 Main fuse 2 Battery 3 Starter relay 4 Starter motor 5 Starting circuit cut off relay 6 Diode 7 Rear brake switch 8 Start switch 9 Neutral switch È TO MAIN SWITCH É FROM MAIN SWITCH The transmission is in neutral the neutral switch is closed or You pull in the rear brake lever the rear brake switch is ON R L...

Page 217: ... fuse Check the main fuse for continuity Refer to CHECKING THE FUSE in chap ter 3 Is the main fuse OK Replace the fuse 2 Battery Check the condition of the battery Refer to CHECKING AND CHARGING THE BATTERY in chapter 3 Specific gravity 1 280 at 20 C 68 F Is the battery OK Refill battery fluid Clean the battery terminals Recharge or replace the battery 3 Starter motor Connect the positive battery ...

Page 218: ...ting circuit cut off relay have continuity between red white and blue white B Y L W Sb R W 1 3 2 Second step Connect the pocket tester Ω 1 to the starting circuit cut off relay coupler as shown Measure the starting circuit cut off relay for continuity as follows Positive tester probe sky blue 4 Negative tester probe black yellow 5 Continuity Positive tester probe black yellow 5 Negative tester pro...

Page 219: ...inuity between red and black Replace the starter relay 6 Main switch Check the main switch for continuity Refer to CHECKING THE SWITCHES Is the main switch OK Replace the main switch 3 4 1 2 L W R W R B 7 Neutral switch Check the neutral switch for continuity Refer to CHECKING THE SWITCHES Is the neutral switch OK Replace the neutral switch 8 Rear brake switch Check the rear brake switch for conti...

Page 220: ...ositive tester probe black yellow 2 Negative tester probe green yellow 1 No continuity NOTE _ When you switch the tester s positive and negative probes the readings in the above chart will be reversed Are the testing readings correct Replace the diode 1 2 G Y B Y 11 Wiring Check the entire starting system s wiring Refer to CIRCUIT DIAGRAM Is the starting system s wiring properly connected and with...

Page 221: ...the order listed 1 Starter motor lead 1 2 Ground lead 1 3 Starter motor 1 For installation reverse the removal pro cedure Disassembling the starter motor Remove the parts in the order listed 1 Yoke 1 Refer to ASSEMBLING THE STARTER MOTOR 2 Armature coil 1 3 Brush 1 4 Bracket 1 For assembly reverse the disassembly procedure ...

Page 222: ...he mica of the commutator must be undercut to ensure proper operation of the commutator 4 Measure armature assembly resistances commutator and insulation Out of specification Replace the starter motor a Measure the armature assembly resis tances with the pocket tester b If any resistance is out of specification replace the starter motor Commutator wear limit 15 5 mm 0 61 in Mica undercut 1 mm 0 04...

Page 223: ...a set 7 Check gear teeth Damage wear Replace the gear 8 Check bearing oil seal O rings Damage wear Replace the defective part s Brush length wear limit 3 5 mm 0 14 in Brush spring force 3 24 4 22 N 320 430 gf 11 66 15 19 oz a EBS00515 ASSEMBLING THE STARTER MOTOR 1 Install bracket brush armature coil yoke NOTE _ Align the projection a on the yoke with the slot b on the bracket ...

Page 224: ...RUN OFF B R W R W L G W GRAY G W W L W R B R W Y R B Sb B Y R W Sb B Y R W B R Br B W B W B B B B W Br R B W R Y R B Br Br Sb Y R R W L R W R R R R R B B B B 5A L W R W L W B B Y Sb L W L W R W Sb Br B R W Br B R W B W B B B B R R 1 4 5 6 9 A 7 8 3 K 2 G F H I J 0 1 C D I magneto 4 Rectifier regulator 5 Main fuse 6 Positive battery lead 7 Battery 8 Negative battery lead ...

Page 225: ...4 YES NO The battery is not being charged Inductive self powered tachome ter P N YU 8036 B Engine tachometer P N 90890 03113 Pocket tester P N YU 03112 C 90890 03112 1 Main fuse Check the main fuse for continuity Refer to CHECKING THE FUSE in chap ter 3 Is the main fuse OK Replace the fuse 2 Battery Check the condition of the battery Refer to CHECKING AND CHARGING THE BATTERY in chapter 3 Specific...

Page 226: ...within specifica tion The charging circuit is OK 4 Charging coil resistance Disconnect the C D I magneto coupler from the wire harness Connect the pocket tester Ω 1 to the charging coils Positive tester probe white terminal 1 Negative tester probe black terminal 2 Measure the charging coil resistance Charging coil resistance 0 72 1 08 Ω at 20 C 68 F between white and black Replace the rectifier re...

Page 227: ...R B R W Y R B Sb B Y R W Sb B Y R W B R Br B W B W B B B B W Br R B W R Y R B Br Br Sb Y R W R B B W B R O R W L R W R R R R R B B B B 5A L W R W L W B L W R W B Y Sb L W L W R W Sb B Y G Y B Y Br B R W Br B R W B W B B Y G Y BLACK BLACK B B G Y B G Y B B B B R R 1 4 5 6 9 A E 7 8 3 K B 2 G F H I J 0 2 Neutral switch 3 Main switch 5 Main fuse 6 Positive battery lead 7 Battery 8 Negative battery le...

Page 228: ...n chap ter 3 Is the main fuse OK Replace the fuse 2 Battery Check the condition of the battery Refer to CHECKING AND CHARGING THE BATTERY in chapter 3 Specific gravity 1 280 at 20 C 68 F Is the battery OK Refill battery fluid Clean the battery terminals Recharge or replace the battery 3 Main switch Check the main switch for continuity Refer to CHECKING THE SWITCHES Is the main switch OK Replace th...

Page 229: ...t bulb socket or both 2 Neutral switch Check the neutral switch for continuity Refer to CHECKING THE SWITCHES Is the neutral switch OK Replace the neutral switch 3 Voltage Connect the pocket tester DC 20 V to the neutral indicator light connectors wire har ness side as shown Positive tester probe brown 1 Negative tester probe sky blue 2 Set the main switch to ON Measure the voltage DC 12 V Is the ...

Page 230: ...Sucked in air Deformed float Worn needle valve Improperly sealed valve seat Improperly adjusted fuel level Improperly set pilot jet Air filter Clogged air filter element ELECTRICAL SYSTEM 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 Faulty spark plug lead Broken body C D I syst...

Page 231: ... Valve train Improperly adjusted valve clearance Improperly adjusted valve timing EBS00538 POOR IDLE SPEED PERFORMANCE POOR IDLE SPEED PERFORMANCE Carburetor Loose pilot jet Clogged pilot jet Clogged pilot air jet Improperly adjusted idle speed throttle stop screw Improper throttle cable play Flooded carburetor Electrical system Faulty battery Faulty spark plug Faulty C D I unit Faulty pickup coil...

Page 232: ...Possible Causes 1 A pronounced hesitation or jerky move ment during acceleration deceleration or sustained speed This must not be con fused with engine surging or transmission characteristics 2 A rolling rumble noticeable at low speed a high pitched whine a clunk from a shaft drive component or area 3 A locked up condition of the shaft drive mechanism no power transmitted from the engine to the re...

Page 233: ...0545 CLUTCH SLIPPING DRAGGING CLUTCH SLIPPING Clutch Loose clutch spring Fatigued clutch spring Worn friction plate Worn clutch plate Incorrectly assembled clutch Engine oil Low oil level Improper quality low viscosity Deterioration CLUTCH DRAGGING Clutch Warped pressure plate Unevenly tensioned clutch springs Loose clutch boss nut Bent clutch plate Swollen friction plate Broken clutch boss Engine...

Page 234: ...551 SHOCK ABSORBER MALFUNCTION MALFUNCTION Bent or damaged damper rod Damaged oil seal lip Fatigued shock absorber spring EBS00552 UNSTABLE HANDLING UNSTABLE HANDLING Handlebar Improperly installed or bent Steering Incorrect toe in Bent steering stem Improperly installed steering stem Damaged bearing or bearing race Bent tie rods Deformed steering knuckles Tires Uneven tire pressures on both sides...

Page 235: ...YAMAHA MOTOR CO LTD 2500 SHINGAI IWATA SHIZUOKA JAPAN PRINTED IN U S A ...

Page 236: ...B B B B R R 1 4 5 6 9 A E 7 8 3 K B C D 2 G F H I J 1 C D I magneto 2 Neutral switch 3 Main switch 4 Rectifier regulator 5 Main fuse 6 Positive battery lead 7 Battery 8 Negative battery lead 9 Starter relay 0 Starter motor A Starting circuit cut off relay B C D I unit C Ignition coil D Spark plug E Diode F Rear brake switch G Engine stop switch frame H Handlebar switch I Start switch J Engine stop...

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Yamaha RAPTOR YFM50S, Service Manual

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