Yamaha RAPTOR 50 Service Manual

LIT-11616-17-13 5YF-28197-10YFM50SSERVICE MANUAL

CLUTCH ...4-33REMOVING THE CLUTCH ...

4 - 11ENGCYLINDER HEADi. If the marks are aligned, temporarily tightenthe camshaft sprocket bolt. If the marks arenot aligned, change the meshing posi

4 - 12ENGCAMSHAFT, ROCKER ARMS AND VALVESEBS00235CAMSHAFT, ROCKER ARMS AND VALVESOrder Job/Part Q’ty RemarksRemoving the camshaft, rocker arms and val

4 - 13ENGOrder Job/Part Q’ty Remarks13 Valve guide 2For installation, reverse the removal pro-cedure.CAMSHAFT, ROCKER ARMS AND VALVES

4 - 14ENGCAMSHAFT, ROCKER ARMS AND VALVESEBS00237REMOVING THE ROCKER ARMS AND CAMSHAFT1. Loosen: • locknuts • adjusters2. Remove: • intake rocker arm

4 - 15ENGCAMSHAFT, ROCKER ARMS AND VALVES2. Remove: • valve cottersNOTE:_ Attach a valve spring compressor 1 andattachment 2 between the valve spring

4 - 16ENGCAMSHAFT, ROCKER ARMS AND VALVES2. Check: • rocker arm shaft Blue discoloration/excessive wear/pitting/scratches → Replace or check the lubri

4 - 17ENGCAMSHAFT, ROCKER ARMS AND VALVESEBS00240CHECKING THE VALVES AND VALVE SPRINGS1. Measure: • stem-to-guide clearanceOut of specification → Repl

4 - 18ENGCAMSHAFT, ROCKER ARMS AND VALVES3. Check: • valve face Pitting/wear → Grind the face. • valve stem end Mushroom shape or diameter larger than

4 - 19ENGCAMSHAFT, ROCKER ARMS AND VALVES8. Measure: • valve seat width a Out of specification → Reface the valveseat.▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼

4 - 20ENGCAMSHAFT, ROCKER ARMS AND VALVESb. Apply molybdenum disulfide oil to the valvestem. c. Install the valve into the cylinder head. d. Turn the

CHAPTER 5CARBURETORCARBURETOR...5-1DISASSEMBLING THE CAR

4 - 21ENGCAMSHAFT, ROCKER ARMS AND VALVES12.Measure: • spring tilt a Out of specification → Replace.Spring tilt limit Inner 2.5°/1.4 mm (2.5°/0.06 in)

4 - 22ENGCAMSHAFT, ROCKER ARMS AND VALVESEBS00243INSTALLING THE CAMSHAFT AND ROCKER ARMS1. Install: • camshaft 1NOTE:_ Install the camshaft groove a f

4 - 23ENGCYLINDER AND PISTONEBS00245CYLINDER AND PISTONOrder Job/Part Q’ty RemarksRemoving the cylinder and pistonRemove the parts in the order listed

4 - 24ENGCYLINDER AND PISTONEBS00247REMOVING THE PISTON1. Remove: • piston pin clips 1 • piston pin 2 • piston 3NOTE:_ Before removing each piston pin

4 - 25ENGCYLINDER AND PISTONb. If out of specification, rebore or replace thecylinder, and replace the piston and pistonrings as a set. c. Measure pis

4 - 26ENGCYLINDER AND PISTONEBS00250CHECKING THE PISTON RINGS1. Measure: • piston ring side clearance Out of specification → Replace the pistonand pis

4 - 27ENGCYLINDER AND PISTONEBS00251CHECKING THE PISTON PIN1. Check: • piston pin Blue discoloration/grooves → Replace thepiston pin and then check th

4 - 28ENGCYLINDER AND PISTONEBS00252INSTALLING THE PISTON1. Install: • piston rings (onto the piston)NOTE:_ • Be sure to install the piston rings so t

4 - 29ENGEBS00253INSTALLING THE CYLINDER1. Install: • cylinder NOTE:_ Install the cylinder with one hand while com-pressing the piston rings with the

4 - 30ENGC.D.I. MAGNETOEBS00256C.D.I. MAGNETOOrder Job/Part Q’ty RemarksRemoving the C.D.I. magnetoRemove the parts in the order listed.Rear fender Re

FRONT AND REAR BRAKES...7-6FRONT BRAKE ...

4 - 31ENGC.D.I. MAGNETOEBS00259REMOVING THE C.D.I. MAGNETO ROTOR1. Remove: • C.D.I. magneto rotor nut • washerNOTE:_ • While holding the C.D.I. magnet

4 - 32ENGC.D.I. MAGNETOEBS00268INSTALLING THE C.D.I. MAGNETO ROTOR1. Install: • woodruff key • C.D.I. magneto rotorNOTE:_ • Before installing the roto

4 - 33ENGCLUTCHEBS00291CLUTCHOrder Job/Part Q’ty RemarksRemoving the clutchRemove the parts in the order listed.Engine oil Drain.Refer to “CHANGING TH

4 - 34ENGOrder Job/Part Q’ty Remarks9 Clutch plate 1 1Refer to “INSTALLING THE CLUTCH”.10 Clutch plate 2 311 Friction plate 2 112 Thrust weight plate

4 - 35ENGCLUTCHEBS00297REMOVING THE CLUTCH1. Remove: • clutch coverNOTE:_ Loosen each screw 1/4 of a turn at a time, instages and in a crisscross patt

4 - 36ENGCLUTCHEBS00301CHECKING THE CLUTCH PLATESThe following procedure applies to all of theclutch plates.1. Check: • clutch plate Damage → Replace

4 - 37ENGCLUTCHEBS00304CHECKING THE CLUTCH BOSS1. Check: • clutch boss splines • clutch boss cam groove• clutch boss one-way cam Damage/pitting/wear →

4 - 38ENGCLUTCHEBS00310INSTALLING THE PRIMARY DRIVE GEAR1. Tighten: • primary drive gear nut 1NOTE:_ Place an aluminum plate 2 between the teethof the

4 - 39ENG3. Install:• friction plate 2 1• clutch plates 2 2• friction plates 1 (with black color marking)3• clutch plate 1 45thrust weight plateasilve

4 - 40ENG5. Install: • clutch housing 1 NOTE:_ Make sure that the primary driven gear teethand primary drive gear teeth mesh correctly. 16. Install:•

CHAPTER 8ELECTRICALELECTRICAL COMPONENTS...8-1CHECKING SWITCH CONTINUITY...

4 - 41ENGCLUTCH9. Install:• thrust weight plate 1• friction plate 2 2• clutch plates 2 3• friction plates 1 4• clutch plate 1 5• pressure plate 6asilv

4 - 42ENGSTARTER CLUTCH AND OIL PUMPEBS00315STARTER CLUTCH AND OIL PUMPOrder Job/Part Q’ty RemarksRemoving the starter clutch and oil pumpRemove the p

4 - 43ENGSTARTER CLUTCH AND OIL PUMPEBS00316E54321Order Job/Part Q’ty RemarksDisassembling the oil pumpRemove the parts in the order listed.1 Oil pump

4 - 44ENGSTARTER CLUTCH AND OIL PUMPEBS00263CHECKING THE STARTER CLUTCH1. Check: • starter clutch rollers 1 Cracks/damage → Replace. 2. Check:• starte

4 - 45ENGSTARTER CLUTCH AND OIL PUMP4. Check: • starter idle gear teeth 1 • starter wheel gear teeth 2 Burrs/clips/roughness/wear → Replace.5. Check:

4 - 46ENGSTARTER CLUTCH AND OIL PUMP3. Measure: • inner-rotor-to-outer-rotor-tip clearance a • outer-rotor-to-oil-pump-housing clearanceb• oil-pump-ho

4 - 47ENGSHIFT SHAFTOrder Job/Part Q’ty RemarksRemoving the shift shaftRemove the parts in the order listed.Clutch assembly Refer to “CLUTCH”.1 Shift

4 - 48ENGEBS01018CHECKING THE SHIFT SHAFT1. Check: • shift shaft 1 Bends/damage/wear → Replace. • shift shaft spring 2 Damage/wear → Replace.EBS01019C

4 - 49ENGCRANKCASEEBS00319CRANKCASE Order Job/Part Q’ty RemarksRemoving the timing chain and sep-arating the crankcaseRemove the parts in the order li

4 - 50ENGCRANKCASEEBS00321CRANKCASE BEARINGSE122LTE222EE2T R..8 Nm (0.8 m • kg, 5.8 ft • Ib)Order Job/Part Q’ty RemarksRemoving the crankcase bearings

POOR IDLE SPEED PERFORMANCE ...9-2POOR IDLE SPEED PERFORMANCE...

4 - 51ENGCRANKCASEEBS00333SEPARATING THE CRANKCASE 1. Separate: • right crankcase • left crankcase▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼▼▼a. Remove

4 - 52ENGCRANKCASEEBS00339CHECKING THE BEARINGS AND OIL SEALS 1. Check: • bearings Clean and lubricate, then rotate the innerrace with a finger. Rough

4 - 53ENGCRANKCASEEBS00341ASSEMBLING THE CRANKCASE 1. Apply: • sealant (Quick Gasket®) or Yamaha bondNo. 1215 1 (to the mating surfaces of both case h

4 - 54ENGEBS00326CRANKSHAFTOrder Job/Part Q’ty RemarksRemoving the crankshaftRemove the parts in the order listed.Crankcase Separate.Refer to “CRANKCA

4 - 55ENGCRANKSHAFTEBS00361CHECKING THE CRANKSHAFT 1. Measure: • crank width a Out of specification → Replace the crank-shaft.2. Measure:• side cleara

4 - 56ENGTRANSMISSIONEBS00345TRANSMISSIONOrder Job/Part Q’ty RemarksRemoving the transmissionRemove the parts in the order listed.Crankcase Separate.R

4 - 57ENGREMOVING THE TRANSMISSION1. Remove:• shift fork guide bar 1• shift fork 2• drive axle/middle drive pinion gear assem-bly 3• shift drum 4NOTE:

4 - 58ENGTRANSMISSIONEBS01103CHECKING THE SHIFT DRUM1. Check: • shift drum grooves Damage/scratches/wear → Replace theshift drum assembly. • shift dru

4 - 59ENGTRANSMISSIONEBS00357INSTALLING THE TRANSMISSION 1. Install: • shift drum 1 • drive axle/middle drive pinion gear assem-bly 2 • shift fork 3 •

4 - 60ENGMIDDLE GEAREBS00363MIDDLE GEAR Order Job/Part Q’ty RemarksRemoving the middle gearRemove the parts in the order listed.Crankcase Separate.Ref

1 - 1GENINFOEBS00009GENERAL INFORMATION MACHINE IDENTIFICATIONEBS00010VEHICLE IDENTIFICATION NUMBERThe vehicle identification number 1 isstamped into

4 - 61ENGMIDDLE GEAREBS00366REMOVING THE MIDDLE DRIVEN SHAFT 1. Remove: • universal joint ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼▼▼a. Remove the cir

4 - 62ENGMIDDLE GEAR3. Remove: • bearing housing assembly 1 ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼▼▼a. Clean the outside of the middle driven shaft

4 - 63ENGMIDDLE GEAR2. Check:• O-ring Damage → Replace. • bearings Pitting/damage → Replace. 3. Check: • universal joint movement Roughness → Replace

4 - 64ENGMIDDLE GEAREBS00373INSTALLING THE MIDDLE DRIVEN SHAFT 1. Install: • bearing retainer▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼▼▼a. Secure the

4 - 65ENGMIDDLE GEAR3. Install: • universal joint ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼▼▼a. Install the yoke into the universal joint. b. Apply wh

4 - 66ENGEBS00376MEASURING THE MIDDLE GEAR BACKLASH 1. Measure: • middle gear lash▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼▼▼a. Temporarily install th

5 - 1CARBEBS00141CARBURETORCARBURETOR48976512T R..7 Nm (0.7 m • kg, 5.1 ft • Ib)3(3)Order Job/Part Q’ty RemarksRemoving the carburetorRemove the parts

5 - 2CARBCARBURETOREBS00144Order Job/Part Q’ty RemarksDisassembling the carburetorRemove the parts in the order listed.NOTE:_ Before disassembling the

5 - 3CARBOrder Job/Part Q’ty Remarks7 Float 1 Refer to “ASSEMBLING THE CARBURE-TOR”.8 Needle valve 1For assembly, reverse the disassemblyprocedure.CAR

5 - 4CARBCARBURETOREBS00146DISASSEMBLING THE CARBURETOR NOTE:_ Before disassembling the carburetor, makesure to note the number of times the pilotscre

1 - 2GENINFOIMPORTANT INFORMATIONEBS00013IMPORTANT INFORMATIONPREPARATION FOR REMOVAL AND DISASSEMBLY1. Before removal and disassembly remove alldirt,

5 - 5CARBCARBURETOR4. Check: • piston valve 1 Scratches/wear/damage → Replace. 5. Check: • carburetor top cover 1 • spring 2 Cracks/damage → Replace.6

5 - 6CARBCARBURETOREBS00150ASSEMBLING THE CARBURETORNOTE:_ Before assembling the carburetor, make sureto turn out the pilot air screw the same numbero

5 - 7CARBCARBURETOREBS00154MEASURING AND ADJUSTING THE FUEL LEVEL1. Measure: • fuel level a Out of specification → Adjust.▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼

6 - 1DRIVEBS00155DRIVE TRAIN TROUBLESHOOTING The following conditions may indicate damaged shaft drive components:NOTE:_ Areas A, B, and C above may b

6 - 2DRIVTROUBLESHOOTINGEBS00156CHECKING NOISES1. Investigate any unusual noises.▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼▼▼a. A “rolling rumble” noi

6 - 3DRIVTROUBLESHOOTING3. Check: • oil leakage▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼▼▼a. Clean the entire machine thoroughly, thendry it. b. Apply

6 - 4DRIVTROUBLESHOOTINGEBS00157TROUBLESHOOTING CHARTWhen basic condition “a” and “b” exist, check the following points: Check the wheel and hub nuts

6 - 5DRIVREAR AXLE/FINAL DRIVE ASSEMBLY AND DRIVESHAFTEBS00178REAR AXLE/FINAL DRIVE ASSEMBLY AND DRIVE SHAFTOrder Job/Part Q’ty RemarksRemoving the re

6 - 6DRIVOrder Job/Part Q’ty Remarks6 Rear axle/final drive assembly 1 Refer to “REMOVING THE REAR AXLE/FINAL DRIVE ASSEMBLY” and “INSTALLING THE REAR

6 - 7DRIVREAR AXLE/FINAL DRIVE ASSEMBLY AND DRIVESHAFTEBS00179REAR AXLE/FINAL DRIVE ASSEMBLYOrder Job/Part Q’ty RemarksDisassembling the rear axle/fin

1 - 3GENINFOIMPORTANT INFORMATIONEBS00016LOCK WASHERS/PLATES AND COTTER PINSAfter removal, replace all lock washers/plates1 and cotter pins. After the

6 - 8DRIVREMOVING THE NUTS 1. Place the machine on a level surface. 2. Loosen: • nuts 1 NOTE:_ • Apply the rear brake lever so that the rearaxle does

6 - 9DRIVREAR AXLE/FINAL DRIVE ASSEMBLY AND DRIVESHAFTEBS00181DISASSEMBLING THE REAR AXLE HOUSING1. Remove: • rear axle housing bearing retainer NOTE:

6 - 10DRIVREAR AXLE/FINAL DRIVE ASSEMBLY AND DRIVESHAFTEBS00190CHECKING THE REAR AXLE1. Check: • rear axle runout a Out of specification → Replace. WA

6 - 11DRIVREAR AXLE/FINAL DRIVE ASSEMBLY AND DRIVESHAFTEBS00195ASSEMBLING THE FINAL GEAR CASE1. Install: • final drive pinion gear assembly• spacer 1•

6 - 12DRIVREAR AXLE/FINAL DRIVE ASSEMBLY AND DRIVESHAFTEBS00196INSTALLING THE REAR AXLE/FINAL DRIVE ASSEMBLY1. Lubricate: • drive shaft • coupling gea

6 - 13DRIVREAR AXLE/FINAL DRIVE ASSEMBLY AND DRIVESHAFTEBS00397INSTALLING THE NUTS 1. Tighten: • nuts 1, 2 ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼▼▼

7 - 1CHASEBS00378CHASSIS FRONT AND REAR WHEELS FRONT WHEELSOrder Job/Part Q’ty RemarksRemoving the front wheelsRemove the parts in the order listed.Pl

7 - 2CHASEBS00379REAR WHEELSOrder Job/Part Q’ty RemarksRemoving the rear wheelsRemove the parts in the order listed.Place the machine on a level surfa

7 - 3CHASFRONT AND REAR WHEELSEBS00383CHECKING THE WHEELSThe following procedure applies to both of thefront and rear wheels.1. Check: • wheel 2. Meas

7 - 4CHASFRONT AND REAR WHEELSWARNING_ Eye protection is recommended whenusing striking tools. c. To install the wheel bearings, reverse theabove sequ

1 - 4GENINFOIMPORTANT INFORMATIONEBS00019CHECKING THE CONNECTIONSCheck the leads, couplers, and connectors forstains, rust, moisture, etc.1. Disconnec

7 - 5CHASFRONT AND REAR WHEELSEBS00391INSTALLING THE WHEELSThe following procedure applies to both of thefront and rear wheels.1. Install: • wheel NOT

7 - 6CHASFRONT AND REAR BRAKESEBS00437FRONT AND REAR BRAKESFRONT BRAKE Order Job/Part Q’ty RemarksRemoving the front brakesRemove the parts in the ord

7 - 7CHASFRONT AND REAR BRAKESREAR BRAKEOrder Job/Part Q’ty RemarksRemoving the rear brakeRemove the parts in the order listed.Refer to “FRONT AND REA

7 - 8CHASOrder Job/Part Q’ty Remarks12 Rear brake cable (lever side) 113 Rear brake switch 114 Rear brake lever 1For installation, reverse the removal

7 - 9CHASFRONT AND REAR BRAKESREMOVING THE BRAKESThe following procedure applies to each brake.1. Remove:• brake camshaft lever• brake shoe wear indic

7 - 10CHASFRONT AND REAR BRAKES2. Check: • brake shoe lining surface Glazed areas → Remove. Use coarse sandpaper.NOTE:_ After using sandpaper, wipe of

7 - 11CHASFRONT AND REAR BRAKES2. Check: • brake drum inner surface Oil/scratches → Remove.ÈFront brake drumÉRear brake drumEBS00442INSTALLING THE FRO

7 - 12CHAS3. Install: • brake shoe plate 1 NOTE:_ When installing the brake shoe plate, align thegroove a of the brake shoe plate with the pro-jection

7 - 13CHAS2. Install: • brake camshaft 1• brake shoe wear indicator plate 2• brake camshaft lever NOTE:_ • Install the brake camshaft so its punch mar

7 - 14CHASSTEERING SYSTEMEBS00444STEERING SYSTEMHANDLEBAROrder Job/Part Q’ty RemarksRemoving the handlebar Remove the parts in the order listed.Handle

1 - 5GENINFOSPECIAL TOOLSEBS00021SPECIAL TOOLSThe following special tools are necessary for complete and accurate tune-up and assembly. Useonly the ap

7 - 15CHASOrder Job/Part Q’ty Remarks9 Upper handlebar holder 2Refer to “INSTALLING THE HANDLE-BAR”.10 Handlebar 111 Lower handlebar holder 1For insta

7 - 16CHASSTEERING SYSTEMEBS00447REMOVING THE HANDLEBAR GRIPS1. Remove: • handlebar grips 1NOTE:_ Blow compressed air between the handlebarand handleb

7 - 17CHASSTEERING SYSTEMEBS00449INSTALLING THE HANDLEBAR1. Install: • lower handlebar holder• handlebar • upper handlebar holders NOTE:_ • Install th

7 - 18CHASSTEERING SYSTEMEBS00451INSTALLING THE REAR BRAKE LEVER1. Install: • rear brake lever 1• handlebar switch 2NOTE:_ • Install the rear brake le

7 - 19CHASSTEERING SYSTEMEBS00454STEERING STEMOrder Job/Part Q’ty RemarksRemoving the steering stemRemove the parts in the order listed.Front fender R

7 - 20CHASSTEERING SYSTEMEBS00455REMOVING THE STEERING STEM1. Remove: • steering stemNOTE:When loosening each tie-rod end nut 1, holdthe tie-rod ball

7 - 21CHASSTEERING SYSTEMEBS00460TIE-RODS AND STEERING KNUCKLESOrder Job/Part Q’ty RemarksRemoving the tie-rods and steering knucklesRemove the parts

7 - 22CHASSTEERING SYSTEMEBS00461REMOVING THE TIE-RODSThe following procedure applies to both of thetie-rods.1. Remove: • tie-rod 1NOTE:_ When removin

7 - 23CHASEBS00465INSTALLING THE TIE-RODSThe following procedure applies to both of thetie-rods.1. Install: • tie-rodNOTE:_ • The tie-rod side which m

7 - 24CHASFRONT SHOCK ABSORBER ASSEMBLIES AND FRONTSWINGARMEBS00468FRONT SHOCK ABSORBER ASSEMBLIES AND FRONT SWINGARMOrder Job/Part Q’ty RemarksRemovi

EBS00001YFM50S SERVICE MANUAL ©2003 by Yamaha Motor Corporation, U.S.A. First Edition, April 2003All rights reserved. Any reproduction or unauthorized

1 - 6GENINFOSPECIAL TOOLS90890-01422YM-37132Axle nut wrench (36 mm)This tool is needed to loosen or tighten the rear axle nut.90890-01430YM-38404Ring

7 - 25CHASFRONT SHOCK ABSORBER ASSEMBLIES AND FRONTSWINGARMEBS00469REMOVING THE FRONT SWINGARM1. Check: • front swingarm free play▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼

7 - 26CHASREAR SHOCK ABSORBER AND REAR SWINGARMEBS00476REAR SHOCK ABSORBER AND REAR SWINGARMOrder Job/Part Q’ty RemarksRemoving the rear shock absorbe

7 - 27CHASREAR SHOCK ABSORBER AND REAR SWINGARMEBS00477REMOVING THE REAR SWINGARM1. Check: • swingarm free play▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼

7 - 28CHASREAR SHOCK ABSORBER AND REAR SWINGARMEBS00479CHECKING THE REAR SWINGARM1. Check: • rear swingarm Bends/cracks/damage → Replace.2. Check: • b

8 - 1– +ELECEBS00500ELECTRICALELECTRICAL COMPONENTS1Main switch2Neutral indicator light3Rear brake switch4Handlebar switch5Battery6Main fuse7Engine st

8 - 2– +ELECCHECKING SWITCH CONTINUITYEBS01028CHECKING SWITCH CONTINUITYCheck each switch for continuity with thepocket tester. If the continuity read

8 - 3–+ELECCHECKING THE SWITCHESEBS01029CHECKING THE SWITCHESCheck each switch for damage or wear, proper connections, and also for continuity between

8 - 4– +ELECCHECKING THE BULBS AND BULB SOCKETSEBS01030CHECKING THE BULBS AND BULB SOCKETSCheck each bulb and bulb socket for damageor wear, proper co

8 - 5– +ELECCHECKING THE BULBS AND BULB SOCKETSWARNING_ Since the headlight bulb gets extremelyhot, keep flammable products and yourhands away from th

8 - 6– +ELECCHECKING THE BULBS AND BULB SOCKETSCHECKING THE CONDITION OF THE BULB SOCKETSThe following procedure applies to all of thebulb sockets. 1.

1 - 7GENINFOSPECIAL TOOLSCompressor90890-04019YM-04019Attachment90890-04108YM-04108Valve spring compressorValve spring compressor attachmentThis tool

8 - 7– +ELECIGNITION SYSTEMEBS00503IGNITION SYSTEMCIRCUIT DIAGRAM(GRAY)(BLACK)(BLACK)(BLACK)W/RY/RWSbSbBSbY/RBW RG/WB/RB/WBW/LW/RG/WB/RBO OSbG/YB/WSbG

8 - 8– +ELECIGNITION SYSTEMEBS01045TROUBLESHOOTINGCheck: 1. spark plug2. ignition spark gap 3. spark plug cap resistance 4. ignition coil resistance 5

8 - 9– +ELECIGNITION SYSTEMEBS01034NOYESEBS01036YESNO2. Ignition spark gap • Disconnect the spark plug cap from thespark plug. • Connect the ignition

8 - 10– +ELECIGNITION SYSTEMEBS01038YESNOEBS01041YESNOEBS01042YESNO4. Ignition coil resistance • Disconnect the ignition coil connectorsfrom the ignit

8 - 11– +ELECIGNITION SYSTEMEBS01040YESNOEBS01099YESNOEBS01047YESNO7. Pickup coil resistance • Disconnect the C.D.I. magneto couplerfrom the wire harn

8 - 12– +ELECELECTRIC STARTING SYSTEMEBS00506ELECTRIC STARTING SYSTEMCIRCUIT DIAGRAM(GRAY)(BLACK)(BLACK)(BLACK)W/RY/RWSbSbBSbY/RBW RG/WB/RB/WBW/LW/RG/

8 - 13– +ELECELECTRIC STARTING SYSTEMEBS00507STARTING CIRCUIT OPERATIONThe starting circuit on this model consists ofthe starter motor, starter relay,

8 - 14– +ELECELECTRIC STARTING SYSTEMEBS01050TROUBLESHOOTINGCheck: 1. main fuse2. battery 3. starter motor 4. starting circuit cut-off relay 5. starte

8 - 15– +ELECELECTRIC STARTING SYSTEMEBS01053YESNO4. Starting circuit cut-off relay First step:• Disconnect the starting circuit cut-off relaycoupler

8 - 16– +ELECELECTRIC STARTING SYSTEMEBS01054YESNOEBS01041YESNOEBS01046YESNOYESNOEBS01057YESNO5. Starter relay • Disconnect the starter relay coupler

1 - 8GENINFOSPECIAL TOOLSBond90890-85505SealantACC-11001-05-01Yamaha bond No. 1215Sealant (Quick Gasket®)This sealant (bond) is used on crankcase mati

8 - 17– +ELECELECTRIC STARTING SYSTEMEBS01060YESNOEBS01059YESNO10.Diode • Remove the diode from the coupler. • Connect the pocket tester (Ω × 1) to th

8 - 18– +ELECSTARTER MOTOREBS01061STARTER MOTOROrder Job/Part Q’ty RemarksRemoving the starter motor Remove the parts in the order listed. 1 Starter m

8 - 19– +ELECSTARTER MOTOREBS01064CHECKING THE STARTER MOTOR1. Check: • commutator Dirt → Clean with 600-grit sandpaper.2. Measure: • commutator diame

8 - 20– +ELECSTARTER MOTOR5. Measure: • brush length a Out of specification → Replace the brushesas a set.6. Measure: • brush spring force Out of spec

8 - 21– +ELECCHARGING SYSTEMEBS00516CHARGING SYSTEMCIRCUIT DIAGRAM(GRAY)(BL(BLACK)(BLACK)W/RY/RWSbSbBSbY/RBW RG/WB/RB/WBW/LW/RG/WB/RBr B/WBONOFFOFFONR

8 - 22– +ELECCHARGING SYSTEMEBS01065TROUBLESHOOTINGCheck: 1. main fuse 2. battery 3. charging voltage 4. charging coil resistance 5. wiring connection

8 - 23– +ELECCHARGING SYSTEMEBS01066NOYESEBS01100YESNOEBS01059YESNO3. Charging voltage • Connect the engine tachometer to thespark plug lead. • Connec

8 - 24– +ELECSIGNAL SYSTEMEBS00521SIGNAL SYSTEMCIRCUIT DIAGRAM(GRAY)(BLACK)(BLACK)(BLACK)W/RY/RWSbSbBSbY/RBW RG/WB/RB/WBW/LW/RG/WB/RSG/YB/W(BLACK)(BBr

8 - 25– +ELECSIGNAL SYSTEMEBS01073TROUBLESHOOTINGCheck: 1. main fuse2. battery 3. main switch 4. wiring connections (of the entire signaling system)NO

8 - 26– +ELECSIGNAL SYSTEMEBS01075CHECKING THE SIGNALING SYSTEMEBS010771. The neutral indicator light fails to come on.YESNOYESNOYESNO1. Neutral indic

2 - 1SPECEBS01001SPECIFICATIONSGENERAL SPECIFICATIONSItem StandardModel code5YF1DimensionsOverall length 1,537 mm (60.5 in)Overall width 825 mm (32.5

9 - 1TRBLSHTGEBS00537TROUBLESHOOTINGNOTE:_ The following troubleshooting does not cover all the possible causes of trouble. It should be helpful,howev

9 - 2TRBLSHTGSTARTING FAILURE/HARD STARTING/POOR IDLE SPEEDPERFORMANCE/POOR MEDIUM AND HIGH-SPEED PERFORMANCECOMPRESSION SYSTEMCylinder and cylinder h

9 - 3TRBLSHTGFAULTY DRIVE TRAINEBS00540FAULTY DRIVE TRAINThe following conditions may indicate damaged shaft drive components:NOTE:_ Areas A, B, and C

9 - 4TRBLSHTGFAULTY GEAR SHIFTING/CLUTCH SLIPPING/DRAGGING/OVERHEATINGEBS00541FAULTY GEAR SHIFTINGHARD SHIFTINGRefer to “CLUTCH SLIPPING/DRAGGING—CLUT

9 - 5TRBLSHTGFAULTY BRAKE/SHOCK ABSORBER MALFUNCTION/UNSTABLE HANDLINGEBS00549FAULTY BRAKEPOOR BRAKING EFFECTFront and rear drum brake• Worn brake sho

YAMAHA MOTOR CO., LTD.2500 SHINGAI IWATA SHIZUOKA JAPANPRINTED IN U.S.A.

YFM50S WIRING DIAGRAM(GRAY)(BLACK)(BLACK)(BLACK)W/RY/RWSbSbBSbY/RBW RG/WB/RB/WBW/LW/RG/WB/RBO OSbG/YB/WSbG/YG/WW/L(BLACK)(BLACK)Br B/WBONOFFOFFONRUNOF

2 - 2SPECGENERAL SPECIFICATIONSFuelType Unleaded gasoline onlyFuel tank capacity 6.8 L (1.50 Imp gal, 1.80 US gal)Fuel reserve amount 0.9 L (0.20 Imp

2 - 3SPECGENERAL SPECIFICATIONSBrakeFront brake type Drum brakeoperation Right hand operationRear brake type Drum brakeoperation Left hand operationSu

2 - 4SPECENGINE SPECIFICATIONSEBS01002ENGINE SPECIFICATIONSItem Standard LimitCylinder headWarp limit ---- 0.05 mm (0.002 in)CylinderBore size 39.000

2 - 5SPECENGINE SPECIFICATIONSRocker arm/rocker arm shaftRocker arm inside diameter 10.000 ~ 10.015 mm(0.3937 ~ 0.3943 in)----Rocker arm shaft outside

2 - 6SPECENGINE SPECIFICATIONSStem-to-guide clearance IN 0.010 ~ 0.037 mm (0.0004 ~ 0.0015 in)0.08 mm (0.0031 in)EX 0.025 ~ 0.052 mm (0.0010 ~ 0.0020

2 - 7SPECENGINE SPECIFICATIONSPistonPiston to cylinder clearance 0.025 ~ 0.045 mm (0.0010 ~ 0.0018 in)0.15 mm (0.0059 in)Piston size “D” 38.960 ~ 38.9

EBS00002NOTICEThis manual was produced by the Yamaha Motor Company primarily for use by Yamaha dealersand their qualified mechanics. It is not possibl

2 - 8SPECENGINE SPECIFICATIONSOil ringDimensions (B × T) 2.0 × 2.0 mm(0.0787 × 0.0787 in)----End gap (installed) 0.20 ~ 0.70 mm(0.0079 ~ 0.0276 in)---

2 - 9SPECENGINE SPECIFICATIONSClutch plate 1Thickness 1.4 mm (0.055 in) ----Quantity 1 ----Maximum warpage ---- 0.06 mm (0.002 in)Clutch plate 2Thickn

2 - 10SPECENGINE SPECIFICATIONSOil pumpOil pump type Trochoid ----Inner-rotor-to-outer-rotor-tip clearance 0.05 ~ 0.07 mm (0.002 ~ 0.003 in)0.15 mm (0

2 - 11SPECCHASSIS SPECIFICATIONSEBS01003CHASSIS SPECIFICATIONSItem Standard LimitFront suspensionShock absorber travel 60 mm (2.36 in) ----Optional sp

2 - 12SPECELECTRICAL SPECIFICATIONSEBS01004ELECTRICAL SPECIFICATIONSItem Standard LimitVoltage12 V ----Ignition systemIgnition timing (B.T.D.C.) 10°/1

2 - 13SPECELECTRICAL SPECIFICATIONSElectric starter systemType Constant mesh ----Starter motorModel/manufacturer ADB4A5/DENSO ----Output 0.2 kW ----Ar

2 - 14SPECTIGHTENING TORQUESEBS01005TIGHTENING TORQUESENGINE TIGHTENING TORQUESPart to be tightened Part nameThread sizeQ’tyTightening torqueRemarksNm

2 - 15SPECTIGHTENING TORQUESEBS01006CHASSIS TIGHTENING TORQUESNeutral switch — M10 1 20 2.0 14Spark arrester tailpipe Screw M6 2 8 0.8 5.8Purging bolt

2 - 16SPECTIGHTENING TORQUESNOTE:1. Before tightening the nuts, apply locking agent (LOCTITE®) to rear axle threads.2. Tighten the inside nut to 110 N

2 - 17SPECHOW TO USE THE CONVERSION TABLE/GENERAL TIGHTENING TORQUE SPECIFICATIONSEBS00022HOW TO USE THE CONVERSION TABLEAll specification data in thi

EBS00004HOW TO USE THIS MANUALMANUAL ORGANIZATIONThis manual consists of chapters for the main categories of subjects. (See “symbols”)1st title 1: Thi

2 - 18SPECLUBRICATION POINTS AND LUBRICANT TYPESEBS00024LUBRICATION POINTS AND LUBRICANT TYPESENGINELubrication points LubricantOil seal lipsLSBearing

2 - 19SPECLUBRICATION POINTS AND LUBRICANT TYPESFinal gear case and rear axle housing mating surfaceSealant (Quick Gasket®)Yamaha Bond No.1215Lubricat

2 - 20SPECOIL FLOW DIAGRAMSEBS00026OIL FLOW DIAGRAMS1Camshaft2Crankshaft3Main axle4Drive axle

2 - 21SPECOIL FLOW DIAGRAMS1 Oil pump2 Oil strainer

2 - 22SPECCABLE ROUTINGEBS00028CABLE ROUTING1Rear brake cable2Throttle cable3Fuel tank breather hose4Carburetor air vent hose5Final gear case breather

2 - 23SPECCABLE ROUTINGÈ Route the rear brake cable to the right of thesteering stem.É Pass the carburetor air vent hose through the holeon the left s

2 - 24SPECCABLE ROUTINGÑ Fasten the carburetor air vent hose with a plastic band. Be sure to not pinch the hose. Install the plasticband with the buck

2 - 25SPECCABLE ROUTING1 Rear brake cable2 Wire harness3 Ignition coil4 Handlebar switch lead5 Rear brake switch lead6 Neutral indicator light lead7 M

2 - 26SPECCABLE ROUTINGÈ 80 mm (3.15 in)É Fasten the rear brake cable, wire harness,crankcase breather hose, and final gear casebreather hose with a p

2 - 27SPECCABLE ROUTING1 Rear brake switch2 Rear brake cable3 Left front brake cable4 Right front brake cable5 Throttle cable6 Fuel tank breather hose

EBS00005SYMBOLSThe following symbols are not relevant toevery machine. Symbols 1 to 9 indicate the subject of eachchapter.1General information 2Specif

2 - 28SPECCABLE ROUTINGÈ Fasten the negative battery lead with the plastic holder.É To starter motorÊ Pass the leads through the hole.Ë To wire harnes

2 - 29SPECCABLE ROUTING1 Throttle cable2 Fuel tank breather hose3 Rear brake cable4 Handlebar switch lead5 Rear brake switch lead6 Air filter joint7 N

3 - 1CHKADJEBS00029PERIODIC CHECKS AND ADJUSTMENTSINTRODUCTIONThis chapter includes all information necessary to perform recommended checks and adjust

3 - 2CHKADJSEAT, FENDERS AND FUEL TANKEBS00033SEAT, FENDERS AND FUEL TANKSEAT AND FRONT PANEL13452Order Job/Part Q’ty RemarksRemoving the seat and fro

3 - 3CHKADJSEAT, FENDERS AND FUEL TANKEBS00037FRONT FENDERT R..7 Nm (0.7 m • kg, 5.1 ft • Ib)4123T R..7 Nm (0.7 m • kg, 5.1 ft • Ib)Order Job/Part Q’t

3 - 4CHKADJSEAT, FENDERS AND FUEL TANKEBS00039REAR FENDER AND FOOTREST BOARDS1652438T R..7 Nm (0.7 m • kg, 5.1 ft • Ib)T R..7 Nm (0.7 m • kg, 5.1 ft •

3 - 5CHKADJ1652438T 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)T R..7 Nm (0.7 m • kg, 5.1

3 - 6CHKADJSEAT, FENDERS AND FUEL TANKEBS00042FUEL TANK21Order Job/Part Q’ty RemarksRemoving the fuel tankRemove the parts in the order listed.Seat an

3 - 7CHKADJEBS00046ENGINEADJUSTING THE TIMING CHAIN TENSIONER1. Remove:• C.D.I. magneto cover• camshaft sprocket coverRefer to “CYLINDER HEAD” in chap

3 - 8CHKADJ5. Install:• camshaft sprocket cover• C.D.I. magneto coverRefer to “CYLINDER HEAD” in chapter 4.ADJUSTING THE VALVE CLEARANCENOTE:_ • The v

EBS00007TABLE OF CONTENTSGENERAL INFORMATIONGEN INFO1SPECIFICATIONSSPEC2PERIODIC CHECKS AND ADJUSTMENTSCHK ADJ3ENGINEENG4CARBURETORCARB5DRIVE TRAINDRI

3 - 9CHKADJADJUSTING THE VALVE CLEARANCENOTE:_ • When the piston is at the Top Dead Center(TDC) on the compression stroke, thereshould be clearance be

3 - 10CHKADJADJUSTING THE VALVE CLEARANCE/ADJUSTING THE ENGINE IDLING SPEED4. Install: • camshaft sprocket cover• exhaust tappet cover• intake tappet

3 - 11CHKADJADJUSTING THE ENGINE IDLING SPEED/ADJUSTING THE THROTTLE LEVER FREE PLAY6. Adjust: • throttle lever free play Refer to “ADJUSTING THE THRO

3 - 12CHKADJADJUSTING THE SPEED LIMITEREBS00053ADJUSTING THE SPEED LIMITERThe speed limiter keeps the carburetor throttlefrom becoming fully-opened ev

3 - 13CHKADJCHECKING THE SPARK PLUGEBS00057CHECKING THE SPARK PLUG1. Remove: • spark plug2. Check: • spark plug type Incorrect → Change.3. Check: • el

3 - 14CHKADJCHECKING THE IGNITION TIMINGEBS00058CHECKING THE IGNITION TIMINGNOTE:_ Engine idling speed and throttle cable free playshould be adjusted

3 - 15CHKADJMEASURING THE COMPRESSION PRESSUREEBS00061MEASURING THE COMPRESSION PRESSURENOTE:_ Insufficient compression pressure will result ina loss

3 - 16CHKADJMEASURING THE COMPRESSION PRESSURE▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼▼▼a. Set the main switch to “ON”. b. With the throttle wide ope

3 - 17CHKADJCHECKING THE ENGINE OIL LEVELEBS00064CHECKING THE ENGINE OIL LEVEL1. Place the machine on a level surface.2. Check: • engine oil level Oil

3 - 18CHKADJCHANGING THE ENGINE OILEBS00068CHANGING THE ENGINE OIL1. Start the engine, warm it up for several min-utes, and then turn it off. 2. Place

CONTENTSCHAPTER 1GENERAL INFORMATIONMACHINE IDENTIFICATION...1-1VEHICLE IDENT

3 - 19CHKADJCLEANING THE AIR FILTER ELEMENTEBS00071CLEANING THE AIR FILTER ELEMENTNOTE:_ There is a check hose 1 at the bottom of theair filter case.

3 - 20CHKADJCLEANING THE AIR FILTER ELEMENT/CLEANING THE SPARK ARRESTERb. Squeeze the excess solvent out of the ele-ment and let it dry.CAUTION:_ Do n

3 - 21CHKADJc. Tap the tailpipe lightly with a soft-face ham-mer or suitable tool, then use a wire brushto remove any carbon deposits from thespark ar

3 - 22CHKADJCHECKING THE FRONT AND REAR BRAKE SHOES/ADJUSTING THE FRONT BRAKECHASSISEBS00079CHECKING THE FRONT AND REAR BRAKE SHOES1. Operate the brak

3 - 23CHKADJADJUSTING THE REAR BRAKEEBS00084ADJUSTING THE REAR BRAKENOTE:_ Before adjusting the rear brake, the rear brakelinings should be checked. C

3 - 24CHKADJCHECKING THE FINAL GEAR OIL LEVEL/CHANGING THE FINAL GEAR OILEBS00101CHECKING THE FINAL GEAR OIL LEVEL1. Place the machine on a level surf

3 - 25CHKADJCHANGING THE FINAL GEAR OIL/CHECKING THE SWINGARM DUST BOOT6. Fill: • final gear case CAUTION:_ Take care not to allow foreign material to

3 - 26CHKADJCHECKING THE STEERING SYSTEMEBS00107CHECKING THE STEERING SYSTEM1. Place the machine on a level surface.2. Check: • steering shaft bushing

3 - 27CHKADJADJUSTING THE TOE-INEBS00108ADJUSTING THE TOE-IN1. Place the machine on a level surface.2. Measure: • toe-in Out of specification → Adjust

3 - 28CHKADJADJUSTING THE TOE-IN/CHECKING THE FRONT ANDREAR SHOCK ABSORBERS▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼▼▼a. Mark both tie-rods ends. This

OIL FLOW DIAGRAMS...2-20CABLE ROUTING ...

3 - 29CHKADJCHECKING THE TIRESEBS00114CHECKING THE TIRESWARNING_ This model is equipped with low pressuretires. It is important that they be inflatedc

3 - 30CHKADJCHECKING THE TIRES1. Measure: • tire pressure Out of specification → Adjust. NOTE:_ • The low-pressure tire gauge 1 is includedas standard

3 - 31CHKADJCHECKING THE TIRES/CHECKING THE WHEELS2. Check: • tire surfaces Wear/damage → Replace. WARNING_ It is dangerous to ride with a worn-out ti

3 - 32CHKADJCHECKING AND LUBRICATING THE CABLES/LUBRICATING THELEVERS, STEERING SHAFT AND STEERING KNUCKLESEBS00117CHECKING AND LUBRICATING THE CABLES

3 - 33CHKADJCHECKING AND CHARGING THE BATTERYEBS00119ELECTRICAL SYSTEMCHECKING AND CHARGING THE BATTERYWARNING_ Batteries generate explosive hydrogen

3 - 34CHKADJCHECKING AND CHARGING THE BATTERY3. Remove: • battery4. Check: • electrolyte level The electrolyte level should be between theminimum leve

3 - 35CHKADJCHECKING AND CHARGING THE BATTERY• Do not use a high-rate battery charger.They force a high-amperage current intothe battery quickly and c

3 - 36CHKADJCHECKING AND CHARGING THE BATTERY7. Check: • battery breather hose and battery vent Obstruction → Clean. Damage → Replace.8. Install: • ba

3 - 37CHKADJCHECKING THE FUSEEBS00121CHECKING THE FUSECAUTION:_ To avoid a short circuit, always set themain switch to “OFF” when checking orreplacing

3 - 38CHKADJCHECKING THE FUSEd. If the fuse immediately blows again, checkthe electrical circuit.WARNING_ Never use a fuse with an amperage ratingothe

ELECTRICAL SYSTEM...3-33CHECKING AND CHARGING THE BATTERY...

4 - 1ENGEBS00198ENGINE ENGINEEXHAUST PIPE/MUFFLER, BREATHER HOSE AND LEADS13452T R..10 Nm (1.0 m • kg, 7.2 ft • Ib)T R..25 Nm (2.5 m • kg, 18 ft • Ib)

4 - 2ENGENGINEEBS00205ENGINE MOUNTING BOLTS32151324T R..33 Nm (3.3 m • kg, 24 ft • Ib)T R..33 Nm (3.3 m • kg, 24 ft • Ib)Order Job/Part Q’ty RemarksRe

4 - 3ENG32151324T R..33 Nm (3.3 m • kg, 24 ft • Ib)T R..33 Nm (3.3 m • kg, 24 ft • Ib)Order Job/Part Q’ty Remarks3 Upper engine mounting nut/bolt 1/1R

4 - 4ENGENGINEREMOVING THE ENGINE1. Remove:• metal clampsNOTE:After removing the metal clamps, slide the dustboot 1 towards the swingarm.1EBS00207INST

4 - 5ENGCYLINDER HEADEBS00218CYLINDER HEADOrder Job/Part Q’ty RemarksRemoving the cylinder headRemove the parts in the order listed.Carburetor assembl

4 - 6ENGOrder Job/Part Q’ty Remarks11 Exhaust side timing chain guide 112 Cylinder head gasket 113 Dowel pin 2For installation, reverse the removal pr

4 - 7ENGCYLINDER HEADEBS00220REMOVING THE CYLINDER HEAD1. Align: •“T” mark on the rotor (with the stationary pointer on the crank-case)▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼

4 - 8ENGCYLINDER HEAD4. Remove: • bolts • nuts• cylinder head 1NOTE:_ Working in a crisscross pattern, loosen eachnut 1/4 of a turn. 1EBS00224CHECKING

4 - 9ENGCYLINDER HEADEBS00230CHECKING THE CYLINDER HEAD 1. Eliminate: • combustion chamber carbon deposits (with a rounded scraper)NOTE:_ Do not use a

4 - 10ENGCYLINDER HEADEBS00233INSTALLING THE CYLINDER HEAD1. Install: • cylinder head 1• nuts • boltsNOTE:_ Tighten the nuts in two stages and a criss