Yamaha VINO YJ50RR Service Manual

YJ50RNSERVICE MANUALLIT-11616-14-50 5LY-28197-E0

CHAPTER 4CHASSISFRONT WHEEL AND BRAKE...4-1CHECKING THE FRONT WHEEL ...

4 - 20CHASHANDLEBAREAS00671 INSTALLING THE HANDLEBAR1. Stand the scooter on a level surface.WARNING@Securely support the scooter so that thereis no da

4 - 21CHASHANDLEBAR4. Install: • throttle grip• throttle cableNOTE:@Lubricate the inside of the throttle grip with athin coat of lithium soap base gre

4 - 22CHASSTEERING HEADSTEERING HEADOrder Job/Part Q’ty RemarksRemoving the lower handlebar holderRemove the parts in the order listed.Footrest board

4 - 23CHASSTEERING HEADOrder Job/Part Q’ty RemarksRemoving the forkRemove the parts in the order listed.1Cover 12 Upper steering stem ring nut 13 Uppe

4 - 24CHASSTEERING HEADEAS00680 REMOVING THE FORK1. Stand the scooter on a level surface.WARNING@Securely support the scooter so that thereis no dange

4 - 25CHASSTEERING HEAD3. Replace: • bearings • bearing races▼▼▼▼ ▼ ▼▼▼▼▼▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼▼▼a. Remove the bearing races from the steeringhea

4 - 26CHASREAR SHOCK ABSORBER ASSEMBLYEAS00685REAR SHOCK ABSORBER ASSEMBLYTR..30 Nm (3.0 m •kg, 22 ft•Ib)TR..15 Nm (1.5 m •kg, 11 ft•Ib)1Order Job/Par

4 - 27CHASREAR SHOCK ABSORBER ASSEMBLYEAS00692 REMOVING THE REAR SHOCK ABSORBER ASSEMBLY1. Stand the scooter on a level surface.WARNING@Securely suppo

5 - 1ENGENGINEENGINE REMOVAL5671316821112101514943TR..84 Nm (8.4 m •kg, 61 ft•Ib)TR..15 Nm (1.5 m •kg, 11 ft•Ib)TR..28 Nm (2.8 m •kg, 20 ft•Ib)TR..11

5 - 2ENGENGINE REMOVAL5671316821112101514943TR..84 Nm (8.4 m •kg, 61 ft•Ib)TR..15 Nm (1.5 m •kg, 11 ft•Ib)TR..28 Nm (2.8 m •kg, 20 ft•Ib)TR..11 Nm (1.

CHAPTER 5ENGINEENGINE REMOVAL...5-1INSTALLING THE ENGINE...

5 - 3ENGENGINE REMOVALEAS00192 INSTALLING THE ENGINE1. Install: • engine mounting bolt/nut 1• bolt (rear shock absorber-lower) 22. Install: • kickstar

5 - 4ENGCYLINDER HEAD, CYLINDER AND PISTONCYLINDER HEAD, CYLINDER AND PISTON910812117845361132TR..14 Nm (1.4 m •kg, 10 ft•Ib)TR..20 Nm (2.0 m •kg, 14

5 - 5ENGCYLINDER HEAD, CYLINDER AND PISTON910812117845361132TR..14 Nm (1.4 m •kg, 10 ft•Ib)TR..20 Nm (2.0 m •kg, 14 ft•Ib)TR..13 Nm (1.3 m•kg, 9.4 ft•

5 - 6ENGCYLINDER HEAD, CYLINDER AND PISTONEAS00253 REMOVING THE CYLINDER AND PISTON1. Remove: • piston pin clip 1• piston pin 2• piston 3CAUTION:@Do n

5 - 7ENGCYLINDER HEAD, CYLINDER AND PISTON▼▼▼▼ ▼ ▼▼▼▼▼▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼▼▼a. Place a straightedge 1 and a thicknessgauge 2 across the cylinde

5 - 8ENGCYLINDER HEAD, CYLINDER AND PISTONb. If out of specification, rebore or replace thecylinder, and replace the piston and pistonrings as a set.

5 - 9ENGCYLINDER HEAD, CYLINDER AND PISTONPiston ring side clearance Top ring 0.03 ~ 0.05 mm(0.0012 ~ 0.0020 in) <Limit>: 0.10 mm (0.0039 in) 2n

5 - 10ENGCYLINDER HEAD, CYLINDER AND PISTON2. Measure: • piston pin outside diameter aOut of specification → Replace the piston pin.Piston pin outside

5 - 11ENGCYLINDER HEAD, CYLINDER AND PISTONEAS00267 INSTALLING THE PISTON AND CYLINDER1. Install: • top ring 1• 2nd ring 2NOTE:@• Be sure to install t

5 - 12ENG3. Install: • cylinder gasket 14. Lubricate: • piston • piston rings • cylinder (with the recommended lubricant)5. Install: • cylinder 2NOTE:

CRANKCASE ...5-37DISASSEMBLING THE CRANKCASE...

5 - 13ENGKICKSTARTEREAS00338 KICKSTARTERSHEAVES COVER 6465321TR..11 Nm (1.1 m •kg, 8.0 ft•Ib)Order Job/Part Q’ty RemarksRemoving the sheave coverRemov

5 - 14ENGKICKSTARTER5621734LSNewOrder Job/Part Q’ty RemarksDisassembling the kickstarter shaftRemove the parts in the order listed.1Kickstarter pinion

5 - 15ENGKICKSTARTEREAS00339 CHECKING THE KICKSTARTER1. Check: • kickstarter shaft• kickstarter pinion gearDamage/wear → Replace.2. Check: • kickstart

5 - 16ENGBELT DRIVEEAS00316 BELT DRIVENew16431256789101112151413TR..30 Nm (3.0 m •kg, 22 ft•Ib)TR..40 Nm (4.0 m •kg, 29 ft•Ib)Order Job/Part Q’ty Rema

5 - 17ENGBELT DRIVENew16431256789101112151413TR..30 Nm (3.0 m •kg, 22 ft•Ib)TR..40 Nm (4.0 m •kg, 29 ft•Ib)Order Job/Part Q’ty Remarks11 Collar 112 Pr

5 - 18ENGBELT DRIVELSLSLSNew3213New8New7960954TR..50 Nm (5.0 m •kg, 36 ft•Ib)Order Job/Part Q’ty RemarksDisassembling the secondary pulleyRemove the p

5 - 19ENGBELT DRIVEEAS00318 REMOVING THE SECONDARY PULLEY AND V-BELT1. Remove: • air shroud•fanRefer to “GENERATOR AND AUTOLUBEPUMP”.2. Remove: • clut

5 - 20ENGBELT DRIVEEAS00317 REMOVING THE PRIMARY SHEAVE1. Remove: • primary sheave nut 1• conical spring washer• kickstarter one-way clutch• claw wash

5 - 21ENGBELT DRIVE2. Measure: • clutch shoe thicknessOut of specification → Replace the clutchshoes as a set.Clutch shoe thickness 4.0 mm (0.157 in)

5 - 22ENGBELT DRIVEEAS00320 CHECKING THE V-BELT1. Check: •V-belt 1Cracks/damage/wear → Replace. Grease/oil → Check the primary and sec-ondary pulleys.

STARTER MOTOR...7-17CHECKING THE STARTER MOTOR ...

5 - 23ENGBELT DRIVEEAS00324 ASSEMBLING THE SECONDARY PULLEY1. Lubricate: • secondary fixed sheave’s inner surface 1• secondary sliding sheave’s inner

5 - 24ENGBELT DRIVE5. Install: • secondary fixed sheave 1• secondary sliding sheave 2• spring • clutch carrier 3NOTE:@Attach the clutch spring holder

5 - 25ENGBELT DRIVE4. Install: • washer 7• primary fixed sheave 8• claw washer 9• kickstarter one-way clutch 0• conical spring washer A• primary sheav

5 - 26ENGBELT DRIVE2. Install: •V-belt 1• secondary pulley 2CAUTION:@Do not allow grease to contact the V-belt,secondary pulley or clutch assembly. NO

5 - 27ENGSTARTER CLUTCH AND STARTER MOTORSTARTER CLUTCH AND STARTER MOTORMLSLSNewTR..13 Nm (1.3 m •kg, 9.4 ft•Ib)TR..8 Nm (0.8 m•kg, 5.8 ft • Ib)89232

5 - 28ENGSTARTER CLUTCH AND STARTER MOTOREAS00351 CHECKING THE STARTER CLUTCH1. Check: • starter clutch rollers 1• starter clutch spring caps 2• start

5 - 29ENGSTARTER CLUTCH AND STARTER MOTOR2. Install:• starter wheel gear 1• starter clutch assembly 2NOTE:@Install the starter clutch assembly 1 while

5 - 30ENGTRANSMISSIONEAS00419TRANSMISSION865471112339NewNewNewGGLSLTLTNewTR..9 Nm (0.9 m•kg, 6.5 ft•Ib)TR..18 Nm (1.8 m •kg, 13 ft•Ib)10Order Job/Part

5 - 31ENGTRANSMISSION865471112339NewNewNewGGLSLTLTNewTR..9 Nm (0.9 m•kg, 6.5 ft•Ib)TR..18 Nm (1.8 m •kg, 13 ft•Ib)10Order Job/Part Q’ty Remarks9Circli

5 - 32ENGTRANSMISSIONEAS00425 CHECKING THE TRANSMISSION1. Check:•drive axle• main axle• secondary drive gearDamage/wear → Replace.2. Check:• bearingRo

OVERHEATING...8-3ENGINE...

5 - 33ENGGENERATOR AND AUTOLUBE PUMPGENERATOR AND AUTOLUBE PUMPSTATOR COIL ASSEMBLY3471862TR..38 Nm (3.8 m •kg, 27 ft•Ib)New5Order Job/Part Q’ty Remar

5 - 34ENGGENERATOR AND AUTOLUBE PUMPAUTOLUBE PUMPTR..6 Nm (0.6 m•kg, 4.3 ft•Ib)216895343NewNewNewLS7Order Job/Part Q’ty RemarksRemoving the autolube p

5 - 35ENGGENERATOR AND AUTOLUBE PUMPEAS00346 REMOVING THE GENERATOR1. Remove: • generator rotor nut 1• washerNOTE:@While holding the generator rotor 2

5 - 36ENGGENERATOR AND AUTOLUBE PUMPEAS00354 INSTALLING THE GENERATOR1. Install: • gasket 1• woodruff key • generator rotor 2• washer • generator roto

5 - 37ENGCRANKCASECRANKCASETR..7 Nm (0.7 m•kg, 5.1 ft • Ib)TR..9 Nm (0.9 m•kg, 6.5 ft•Ib)TR..11 Nm (1.1 m •kg, 8.0 ft•Ib)LSLTLT77891011432165(6)NewNew

5 - 38ENGCRANKCASETR..7 Nm (0.7 m•kg, 5.1 ft • Ib)TR..9 Nm (0.9 m•kg, 6.5 ft•Ib)TR..11 Nm (1.1 m •kg, 8.0 ft•Ib)LSLTLT77891011432165(6)NewNewNewOrder

5 - 39ENGCRANKCASEEAS00385 DISASSEMBLING THE CRANKCASE1. Remove: • crankcase screws 1NOTE:@Loosen each screw 1/4 of a turn at a time, instages and in

5 - 40ENGCRANKCASEEAS00401 CHECKING THE BEARINGS AND OIL SEALS1. Check: • bearings Clean and lubricate the bearings, thenrotate the inner race with yo

5 - 41ENGEAS00416 ASSEMBLING THE CRANKCASE1. Apply: • sealant (onto the crankcase mating surfaces)NOTE:@Do not allow any sealant to come into contactw

5 - 42ENGCRANKSHAFTEAS00381 CRANKSHAFT321243EEENewNewLSLSOrder Job/Part Q’ty RemarksRemoving the crankshaftRemove the parts in the order listed.Engine

1 - 1GENINFOEAS00015 GENERAL INFORMATION SCOOTER IDENTIFICATIONEAS00017 VEHICLE IDENTIFICATION NUMBERThe vehicle identification number 1 isstamped int

5 - 43ENGCRANKSHAFTEAS00388 REMOVING THE CRANKSHAFT ASSEMBLY1. Remove: • crankshaft assembly 1NOTE:@• Remove the crankshaft assembly with thecrankcase

5 - 44ENGCRANKSHAFT4. Check: • bearing Cracks/damage/wear → Replace. EAS00408 INSTALLING THE CRANKSHAFT1. Install: • crankshaft installing tool2. Inst

6 - 1CARBCARBURETIONCARBURETOR21345679108Order Job/Part Q’ty RemarksRemoving the carburetorRemove the parts in the order listed.Center cover, side cov

6 - 2CARBCARBURETOR14532EDCBA09687Order Job/Part Q’ty RemarksDisassembling the carburetorRemove the parts in the order listed.NOTE:@Before disassembli

6 - 3CARBCARBURETOR14532EDCBA09687Order Job/Part Q’ty Remarks8O-ring 19Float pivot pin 10Float 1ANeedle valve 1BMain jet 1CNeedle jet 1DPilot jet 1ECa

6 - 4CARBCARBURETOREAS00485 CHECKING THE CARBURETORNOTE:Before disassembling the carburetor, makesure to note the number of times the pilot airscrew i

6 - 5CARBCARBURETOR7. Check: • throttle valve 1Damage/scratches/wear→ Replace. 18. Check: • jet needle kit 1• needle jet 2• main jet 3• pilot jet 4Ben

6 - 6CARBCARBURETOR2. Install: • needle valve 1• float 2• float pivot pin 3• screw 423413. Install: • float chamber 114. Install: • starter plunger ki

6 - 7CARBCARBURETOREAS00499 MEASURING AND ADJUSTING THE FLOAT HEIGHT1. Measure: • float height aOut of specification → Replace the needlevalve.▼▼▼▼ ▼

6 - 8CARBCARBURETOR▲▲▲▲ ▲ ▲▲▲▲▲▲▲▲▲ ▲ ▲▲▲▲ ▲ ▲▲▲▲ ▲ ▲▲▲▲ ▲▲▲Starter plunger opens.Perform step (3).Starter plunger closes.Replace the auto-choke assem

1 - 2GENINFOIMPORTANT INFORMATIONEAS00020 IMPORTANT INFORMATIONPREPARATION FOR REMOVAL AND DISASSEMBLY1. Before removal and disassembly, remove alldir

7 - 1–+ELECEAS00729 ELECTRICALELECTRICAL COMPONENTS1Main switch2Starter relay3Fuel sender4Oil level switch5CDI unit6Rectifier/regulator7Main fuse8Batt

7 - 2–+ELECSWITCHESEAS00730 SWITCHESCHECKING SWITCH CONTINUITYCheck each switch for continuity with thepocket tester. If the continuity reading is inc

7 - 3–+ELECCHECKING THE SWITCHESEAS00731 CHECKING THE SWITCHESCheck each switch for damage or wear, proper connections, and also for continuity betwee

7 - 4–+ELECCHECKING THE SWITCHES1Front brake light switch2Turn signal switch3Dimmer switch4Horn switch5Main switch6Rear brake light switch7Start switc

7 - 5–+ELECCHECKING THE BULBS AND BULB SOCKETSEAS00733 CHECKING THE BULBS AND BULB SOCKETSCheck each bulb and bulb socket for damageor wear, proper co

7 - 6–+ELECCHECKING THE BULBS AND BULB SOCKETSCHECKING THE CONDITION OF THE BULBSThe following procedure applies to all of thebulbs.1. Remove: • bulbW

7 - 7–+ELECCHECKING THE BULBS AND BULB SOCKETSCHECKING THE CONDITION OF THE BULB SOCKETSThe following procedure applies to all of thebulb sockets. 1.

7 - 8–+ELECIGNITION SYSTEMEAS00734 IGNITION SYSTEMCIRCUIT DIAGRAMOFFONRBrGyBrGyRGy BrR R W123OOBCDBR R RBBBBBBrBL/WL/YY/RWY/RY/RW/L W/LRRRRG/YRL/W4Y/R

7 - 9–+ELECIGNITION SYSTEMEAS00736 TROUBLESHOOTINGCheck:1. main fuse2. battery 3. spark plug 4. ignition spark gap 5. spark plug cap resistance 6. ign

7 - 10–+ELECEAS00742 NOYESEAS00744 YESNO4. Ignition spark gap • Disconnect the spark plug cap from thespark plug. • Connect the ignition checker/dynam

1 - 3GENINFOIMPORTANT INFORMATIONEAS00024 BEARINGS AND OIL SEALSInstall bearings and oil seals so that the manu-facturer’s marks or numbers are visibl

7 - 11–+ELECEAS00746 YESNOEAS00748 YESNOEAS00749 YESNO6. Ignition coil resistance • Disconnect the ignition coil connectorsfrom the ignition coil term

7 - 12–+ELECEAS00750 YESNOEAS00754 YESNO9. Engine stop switch • Check the engine stop switch for continu-ity. Refer to “CHECKING THE SWITCHES”. • Is t

7 - 13–+ELECELECTRIC STARTING SYSTEMEAS00755 ELECTRIC STARTING SYSTEMCIRCUIT DIAGRAMOFFONRBrGyBrGyRGy BrR R W123OOBCDBR R RBBBBBBrBL/WL/YY/RWY/RY/RW/L

7 - 14–+ELECELECTRIC STARTING SYSTEMEAS00757 TROUBLESHOOTINGCheck:1. main fuse 2. battery 3. starter motor 4. starter relay 5. main switch 6. engine s

7 - 15–+ELECEAS00761 YESNOEAS00749 YESNOEAS00750 YESNOEAS00764 YESNOYESNO4. Starter relay • Remove the starter relay from the wireharness. • Connect t

7 - 16–+ELECYESNOEAS00766 YESNO9. Rear brake light switch • Check the rear light switch for continuity.Refer to “CHECKING THE SWITCHES”• Is the rear b

7 - 17–+ELECSTARTER MOTOREAS00767 STARTER MOTOROrder Job/Part Q’ty RemarksRemoving the starter motorRemove the parts in the order listed.Air shroud Re

7 - 18–+ELECEAS00768123456LSNewOrder Job/Part Q’ty RemarksDisassembling the starter motorRemove the parts in the order listed.1O-ring 12Starter motor

7 - 19–+ELECSTARTER MOTOREAS00769 CHECKING THE STARTER MOTOR1. Check: • commutator Dirt → Clean with 600-grit sandpaper.2. Measure: • commutator diame

7 - 20–+ELECSTARTER MOTORb. If any resistance is out of specification,replace the starter motor. ▲▲▲▲ ▲ ▲▲▲▲▲▲▲▲▲ ▲ ▲▲▲▲ ▲ ▲▲▲▲ ▲ ▲▲▲▲ ▲▲▲Armature coi

1 - 4GENINFOIMPORTANT INFORMATIONEAS00026 CHECKING THE CONNECTIONSCheck the leads, couplers, and connectors forstains, rust, moisture, etc.1. Disconne

7 - 21–+ELECCHARGING SYSTEMEAS00773 CHARGING SYSTEMCIRCUIT DIAGRAMRBrGyBrGyRR R W23OBR R RBBBBBBrBL/WL/YY/RWY/RY/RW/L W/LRRRRG/YRL/W4Y/RWBRRL/WRG/YRRR

7 - 22–+ELECEAS00774 TROUBLESHOOTINGCheck:1. main fuse 2. battery 3. charging voltage 4. wiring (of the entire charging system)NOTE:@• Before troubles

7 - 23–+ELECNOYESEAS00779 YESNONOTE:@Make sure the battery is fully charged. • Is the charging voltage within specifica-tion?The charging circuitis OK

7 - 24–+ELECLIGHTING SYSTEMEAS00780 LIGHTING SYSTEMCIRCUIT DIAGRAMOFFONRBrGyBrGyRGy BrR R W123OOBCDBR R RBBBBBBrBL/WL/YY/RWY/RY/RW/L W/LRRRRG/YRL/W4Y/

7 - 25–+ELECEAS00782 TROUBLESHOOTINGCheck:1. main fuse2. battery 3. main switch 4. dimmer switch 5. wiring (of the entire charging system)NOTE:@• Befo

7 - 26–+ELECEAS00787 YESNOEAS00788 CHECKING THE LIGHTING SYSTEM1. The headlight and the high beam indicatorlight fail to come on.YESNOYESNO5. Wiring•

7 - 27–+ELECEAS00776 YESNOEAS00789 2. The meter light fails to come on.YESNOYESNOEAS00790 3. The tail/brake light fails to come on.YESNO4. Source coil

7 - 28–+ELECYESNO2. Voltage • Connect the pocket tester (DC 20 V) to thetail/brake light coupler (wire harness side)as shown.Positive tester probe → b

7 - 29–+ELECEAS00793 SIGNALING SYSTEMCIRCUIT DIAGRAMOFFONRBrGyBrGyRGy BrR R W123OOBCDBR R RBBBBBBrBL/WL/YY/RWY/RY/RW/L W/LRRRRG/YRL/W4Y/RWBRRL/WRG/YRR

7 - 30–+ELEC1Main switch 2Battery3Main fuseERear brake light switchFFront brake light switchGTail/brake lightHOil level gaugeIDiodeJTurn signal relayK

1 - 5GENINFOEAS00027 SPECIAL TOOLSThe following special tools are necessary for complete and accurate tune-up and assembly. Useonly the appropriate sp

7 - 31–+ELECEAS00794 TROUBLESHOOTINGCheck:1. main fuse 2. battery 3. main switch 4. wiring (of the entire signaling system)NOTE:@• Before troubleshoot

7 - 32–+ELECEAS00796 CHECKING THE SIGNALING SYSTEM1. The horn fails to sound.YESNOYESNONOYES1. Horn switch• Check the horn switch for continuity. Refe

7 - 33–+ELECYESNOEAS00798 2. The tail/brake light fails to come on.YESNOYESNOYESNO4. Voltage • Connect the pocket tester (DC 20 V) to thehorn connecto

7 - 34–+ELECEAS00799 3. The turn signal light, turn signal indicatorlight or both fail to blink.YESNOYESNOYESNO1. Turn signal indicator light bulb and

7 - 35–+ELECYESNOYESNO4. Voltage • Connect the pocket tester (DC 20 V) to theturn signal relay coupler (wire harnessside) as shown.Positive tester pro

7 - 36–+ELECEAS00802 5. The oil level warning light fails to come on.YESNOYESNOYESNO1. Oil level warning light bulb and socket• Check the oil level wa

7 - 37–+ELECYESNOEAS00803 6. The fuel level indicator light fails to come on.YESNOEAS00804 YESNO4. Voltage • Connect the pocket tester (DC 20 V) to th

7 - 38–+ELECYESNOYESNO3. Fuel level gauge • Set the main switch to “ON”.• Move the float up 1 or down 2.• Check that the fuel level gauge needlemoves

7 - 39–+ELECAUTO CHOKE SYSTEMAUTO CHOKE SYSTEMCIRCUIT DIAGRAMOOBBBrBL/WL/YWY/RY/RW/L W/LRW/LBWY/RWW/LW/RY/RLACK)0BABBBY/R(BLACK)(BLACK)(BLACK)BOL/WBrB

7 - 40–+ELECTROUBLESHOOTINGCheck:1. auto choke resistance2. lighting coil resistance3. voltageNOTE:@• Before troubleshooting, remove the followingpart

EAS00001 YJ50RNSERVICE MANUAL ©2000 by Yamaha Motor Corporation, U.S.A.First edition, December, 2000All rights reserved. Any reproduction or unauthori

1 - 6GENINFOYU-01701Sheave holderThis tool is used to hold the clutch hous-ing when removing or installing the clutch housing nut.YU-03112Pocket teste

7 - 41–+ELECYESNO3. Voltage • Connect the pocket tester (AC 20 V) to theauto choke lead.Tester positive probe → yellow/red 1Tester negative probe → bl

8 - 1TRBLSHTGEAS00845 TROUBLESHOOTINGNOTE:@The following guide for troubleshooting does not cover all the possible causes of trouble. It shouldbe help

8 - 2TRBLSHTGINCORRECT ENGINE IDLING SPEED/POOR MEDIUM-AND-HIGH-SPEED PERFORMANCE/FAULTY CLUTCHEAS00847 INCORRECT ENGINE IDLING SPEEDENGINEAir filter•

8 - 3TRBLSHTGOVERHEATING/POOR BRAKING PERFORMANCE/UNSTABLE HANDLINGEAS00854 OVERHEATINGENGINECylinder head and piston• Heavy carbon buildupEngine oil

8 - 4TRBLSHTGFAULTY LIGHTING OR SIGNALING SYSTEMEAS00866 FAULTY LIGHTING OR SIGNALING SYSTEMHEADLIGHT DOES NOT LIGHT• Wrong headlight bulb • Too many

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

YJ50RN WIRING DIAGRAM1 Main switch2 Battery3 Main fuse4 Rectifier/regulator5 Right handlebar switch6 Start switch7 Engine stop switch8 Starter relay9

1 - 7GENINFOACC-1100-15-01Quick Gasket®This sealant is used to seal to mating surfaces (e.g., crankcase mating sur-faces).Tool No. Tool name/Function

2 - 1SPECSPECIFICATIONSGENERAL SPECIFICATIONSItem Standard LimitModel code5LY1 ----DimensionsOverall length 1,630 mm (64.1 in) ----Overall width 630 m

2 - 2SPECENGINE SPECIFICATIONSENGINE SPECIFICATIONS Item Standard LimitEngineEngine type Air-cooled, 2-stroke ----Induction system Reed valve ----Disp

2 - 3SPECENGINE SPECIFICATIONSPistonPiston-to-cylinder clearance 0.03 ~ 0.05 mm (0.0012 ~ 0.0020 in) 0.10 mm (0.0039 in)Diameter D 39.952 ~ 39.969 mm

2 - 4SPECENGINE SPECIFICATIONSCrankshaftWidth A 37.90 ~ 37.95 mm (1.492 ~ 1.494 in) ----Max. runout C ---- 0.03 mm (0.0012 in)Big end side clearance D

2 - 5SPECENGINE SPECIFICATIONSCarburetorModel (manufacturer) × quantity Y14P/1 (TEIKEI) × 1 ----Throttle cable free play (at the flange of the throttl

2 - 6SPECCHASSIS SPECIFICATIONSCHASSIS SPECIFICATIONSItem Standard LimitFrameFrame type Steel tube underbone ----Caster angle 25° ----Trail 71 mm (2.8

2 - 7SPECCHASSIS SPECIFICATIONSFront brakeBrake type Drum brake ----Operation Right-hand operation ----Brake lever free play (at lever end) 10 ~ 20 mm

2 - 8SPECCHASSIS SPECIFICATIONSRear suspensionSuspension type Unit swing ----Rear shock absorber assembly type Coil spring/oil damper ----Rear shock a

EAS00002 NOTICEThis manual was produced by the Yamaha Motor Company, Ltd. primarily for use by Yamaha deal-ers and their qualified mechanics. It is no

2 - 9SPECELECTRICAL SPECIFICATIONSELECTRICAL SPECIFICATIONSItem Standard LimitSystem voltage12 V ----Ignition systemIgnition system type DC.CDI ----Ig

2 - 10SPECELECTRICAL SPECIFICATIONSElectric starting systemSystem type Constant mesh ----Starter motorModel (manufacturer) 5BM (YAMAHA) ----Power outp

2 - 11SPECCONVERSION TABLE/GENERAL TIGHTENING TORQUE SPECIFICATIONSEAS00028CONVERSION TABLEAll specification data in this manual are listedin SI and M

2 - 12SPECTIGHTENING TORQUESTIGHTENING TORQUESENGINE TIGHTENING TORQUESPart to be tightened Part nameThread sizeQ’tyTightening torqueRemarksNm m·kgf f

2 - 13SPECTIGHTENING TORQUESCHASSIS TIGHTENING TORQUESPart to be tightened Thread sizeTightening torqueRemarksNm m·kgf ft·lbEngine mounting:Engine mou

2 - 14SPECLUBRICATION POINTS AND LUBRICANT TYPESLUBRICATION POINTS AND LUBRICANT TYPESENGINELubrication Point SymbolOil seal lipsLSO-ringsLSBearingsEP

2 - 15SPECLUBRICATION POINTS AND LUBRICANT TYPESCHASSIS Lubrication Point SymbolOil seal lipsLSO-ringsLSBearingsLSSpeedometer drive gearLSFront brake

2 - 16SPECCABLE ROUTINGCABLE ROUTING1Front brake cable2Rear brake cable3Front turn signal leads4Fuel level gauge coupler5Flasher relay6Horn lead7Throt

2 - 17SPECCABLE ROUTING1Front turn signal leads (left)2Headlight coupler3Fuel level gauge coupler4Flasher relay lead5Horn lead6Front turn signal leads

2 - 18SPECCABLE ROUTINGÊPass the front brake cable and speedometercable through the cable guide.ËPass the front brake cable and speedometercable throu

EAS00007 HOW TO USE THIS MANUALThis manual is intended as a handy, easy-to-read reference book for the mechanic. Comprehensiveexplanations of all inst

2 - 19SPECCABLE ROUTING1Tail/brake light coupler2Oil level switch lead3Battery leads4Battery5Starter motor coupler6AC magneto coupler7Auto choke coupl

2 - 20SPECCABLE ROUTINGÈFasten the wire harness with a plastic lockingtie.ÉFasten the wire harness, throttle cable and rearbrake cable with plastic lo

2 - 21SPECCABLE ROUTING1Ignition coil lead2Ignition coil3Battery4Starter relay5Oil hose6Oil level switch lead7AC magneto lead8Fuel sender lead9Tail/br

2 - 22SPECCABLE ROUTINGÈFasten the wire harness at the white tapemarker with a plastic locking tie.ÉPass the spark plug lead through the bottomcowling

3 - 1CHKADJEAS00036 PERIODIC CHECKS AND ADJUSTMENTSINTRODUCTIONThis chapter includes all information necessary to perform recommended checks and adjus

3 - 2CHKADJEAU00479NOTE:The air filter needs more frequent service if you are riding in unusually wet or dusty areas.EAU03903NOTE:From 6,000 mi (9,000

3 - 3CHKADJSIDE COVERS AND FOOTREST BOARDEAS00038 SIDE COVERS AND FOOTREST BOARD6391881113151012144161721577TR..15 Nm (1.5 m •kg, 11 ft•Ib)TR..10 Nm (

3 - 4CHKADJSIDE COVERS AND FOOTREST BOARD6391881113151012144161721577TR..15 Nm (1.5 m •kg, 11 ft•Ib)TR..10 Nm (1.0 m •kg, 7.2 ft•Ib)TR..7 Nm (0.7 m•kg

3 - 5CHKADJFRONT PANEL AND LEG SHIELDEAS00040 FRONT PANEL AND LEG SHIELD19234571368101112Order Job/Part Q’ty RemarksRemoving the front panel and leg s

3 - 6CHKADJFRONT PANEL AND LEG SHIELD19234571368101112Order Job/Part Q’ty Remarks11 Fuel level gauge 112 Main switch cover 113 Leg shield 1For install

EAS00009 SYMBOLSThe following symbols are not relevant toevery vehicle. Symbols1 to 8 indicate the subject of eachchapter.1General information 2Specif

3 - 7CHKADJADJUSTING THE ENGINE IDLING SPEEDEAS00053 ADJUSTING THE ENGINE IDLING SPEEDNOTE:@Prior to adjusting the engine idling speed, thecarburetor

3 - 8CHKADJADJUSTING THE ENGINE IDLING SPEED/ADJUSTING THE THROTTLE CABLE FREE PLAY6. Adjust: • throttle cable free play aRefer to “ADJUSTING THE THRO

3 - 9CHKADJBLEEDING THE AUTOLUBE PUMPNOTE:The Autolube pump and delivery lines must bebled on the following occasions.• Setting up a new scooter out o

3 - 10CHKADJNOTE:• Check the bleed screw gasket, and if dam-aged, replace with a new one.• Place a oil pan under the autolube pump tocatch oil.▲▲▲▲ ▲

3 - 11CHKADJCHECKING THE SPARK PLUG/MEASURING THE COMPRESSION PRESSURE4. Check: • electrodes 1Damage/wear → Replace the spark plug. • insulator 2Abnor

3 - 12CHKADJMEASURING THE COMPRESSION PRESSURECAUTION:@Before removing the spark plug, use com-pressed air to blow away any dirt accumu-lated in the s

3 - 13CHKADJMEASURING THE COMPRESSION PRESSURE/CHECKING THE ENGINE OIL LEVELd. If the compression pressure is below theminimum specification, squirt a

3 - 14CHKADJ3. Remove:• oil tank coverRefer to “SIDE COVERS AND FOOTREST-BOARD”.• oil tank cap 14. Fill:• engine oilMake sure the engine oil is at the

3 - 15CHKADJ5. Remove:• transmission oil drain bolt 1• gasket16. Drain:• transmission oil(completely from the transmission case)7. Check:• O-ringDamag

3 - 16CHKADJCLEANING THE AIR FILTER ELEMENTEAS00089 CLEANING THE AIR FILTER ELEMENTNOTE:@On the bottom of the air filter case is a checkhose1. If dust

EAS00011 TABLE OF CONTENTSGENERAL INFORMATIONGENINFO1SPECIFICATIONSSPEC2PERIODIC CHECKS AND ADJUSTMENTSCHKADJ3CHASSISCHAS4ENGINEENG5CARBURETIONCARB6EL

3 - 17CHKADJCLEANING THE AIR FILTER ELEMENT/CHECKING THE CARBURETOR JOINT/CHECKING THE FUEL AND VACUUM HOSES6. Install: • air filter element • air fil

3 - 18CHKADJCHECKING THE FUEL AND VACUUM HOSES/CHECKING THE CRANKCASE BREATHER HOSE/CHECKING THE EXHAUST SYSTEM2. Check: • vacuum hose 1• fuel hoses 2

3 - 19CHKADJADJUSTING THE FRONT BRAKE/ADJUSTING THE REAR BRAKEEAS00109 CHASSISADJUSTING THE FRONT BRAKE1. Check: • brake lever free play aOut of speci

3 - 20CHKADJADJUSTING THE REAR BRAKE/CHECKING THE BRAKE SHOES/CHECKING AND ADJUSTING THE STEERING HEAD2. Adjust: • brake lever free play▼▼▼▼ ▼ ▼▼▼▼▼▼▼

3 - 21CHKADJCHECKING AND ADJUSTING THE STEERING HEADNOTE:@Place the scooter on a suitable stand so thatthe front wheel is elevated. 2. Check: • steeri

3 - 22CHKADJCHECKING AND ADJUSTING THE STEERING HEAD/CHECKING THE FRONT SHOCK ABSORBER/CHECKING THE TIRES5. Install:• Steering shaft bolt 56. Install:

3 - 23CHKADJCHECKING THE TIRESWARNING@• The tire pressure should only be checkedand regulated when the tire temperatureequals the ambient air temperat

3 - 24CHKADJCHECKING THE TIRESWARNING@• Do not use a tubeless tire on a wheeldesigned only for tube tires to avoid tirefailure and personal injury fro

3 - 25CHKADJCHECKING THE TIRES/CHECKING THE WHEELSRear tireWARNING@New tires have a relatively low grip on theroad surface until they have been slight

3 - 26CHKADJCHECKING AND LUBRICATING THE CABLES/LUBRICATING THE LEVERS/LUBRICATING THE CENTERSTANDEAS00170 CHECKING AND LUBRICATING THE CABLESThe foll

MEMO

3 - 27CHKADJCHECKING AND CHARGING THE BATTERYEAS00179 ELECTRICAL SYSTEMCHECKING AND CHARGING THE BATTERYWARNING@Batteries generate explosive hydrogen

3 - 28CHKADJCHECKING AND CHARGING THE BATTERYNOTE:@Since MF batteries are sealed, it is not possi-ble to check the charge state of the battery bymeasu

3 - 29CHKADJCHECKING AND CHARGING THE BATTERYb. Check the charge of the battery, as shownin the charts and the following example.Examplec. Open-circui

3 - 30CHKADJCHECKING AND CHARGING THE BATTERY• If the battery becomes hot to the touch atany time during the charging process,disconnect the battery c

3 - 31CHKADJCharging method using a variable voltage chargerCHECKING AND CHARGING THE BATTERY

3 - 32CHKADJCharging method using a constant voltage chargerCHECKING AND CHARGING THE BATTERY3

3 - 33CHKADJ6. Install: • battery7. Connect: • battery lead coupler(to the battery terminals)8. Check: • battery terminals Dirt → Clean with a wire br

3 - 34CHKADJCHECKING THE FUSEEAS00181 CHECKING THE FUSECAUTION:@To avoid a short circuit, always set themain switch to “OFF” when checking orreplacing

3 - 35CHKADJCHECKING THE FUSE/REPLACING THE HEADLIGHTWARNING@Never use a fuse with an amperage ratingother than that specified. Improvising orusing a

3 - 36CHKADJREPLACING THE HEADLIGHT BULB/ADJUSTING THE HEADLIGHT BEAM6. Install: • headlight bulbSecure the new headlight bulb with theheadlight bulb

CONTENTSCHAPTER 1GENERAL INFORMATIONSCOOTER IDENTIFICATION...1-1VEHICLE IDENTI

3 - 37CHKADJADJUSTING THE HEADLIGHT BEAM2. Adjust: • headlight beam (horizontally)▼▼▼▼ ▼ ▼▼▼▼▼▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼▼▼a. Turn the adjusting knob

4 - 1CHASEAS00517 CHASSISFRONT WHEEL AND BRAKE697342815TR..48 Nm (4.8 m •kg, 35 ft•Ib)Order Job/Part Q’ty RemarksRemoving the front wheel and brakeRem

4 - 2CHASFRONT WHEEL AND BRAKE697342815TR..48 Nm (4.8 m •kg, 35 ft•Ib)Order Job/Part Q’ty Remarks8 Front brake shoe plate 19Spacer 1For installation,

4 - 3CHASFRONT WHEEL AND BRAKE124356LSLSNewOrder Job/Part Q’ty RemarksDisassembling the front wheelRemove the parts in the order listed.1Oil seal 1Ref

4 - 4CHASFRONT WHEEL AND BRAKE1205497NewNewA86TR..4 Nm (0.4 m•kg, 2.9 ft • Ib)LSLS3Order Job/Part Q’ty RemarksDisassembling the front brake shoeplateR

4 - 5CHASFRONT WHEEL AND BRAKEEAS00525 CHECKING THE FRONT WHEEL1. Check: • wheel axle Roll the wheel axle on a flat surface. Bends → Replace.WARNING@D

4 - 6CHASFRONT WHEEL AND BRAKE5. Replace: • oil seal • wheel bearings▼▼▼▼ ▼ ▼▼▼▼▼▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼▼▼a. Clean the outside of the front whee

4 - 7CHASFRONT WHEEL AND BRAKEEAS00536 CHECKING THE BRAKEThe following procedure applies to all of thebrake shoes.1. Check: • brake shoe lining Glazed

4 - 8CHASFRONT WHEEL AND BRAKEEAS00537 ASSEMBLING THE BRAKE SHOE PLATE1. Install: • brake camshaft 1• spring • brake shoe wear indicator 2• brake cams

4 - 9CHASFRONT WHEEL AND BRAKE5. Tighten: • wheel axle nutWARNING@Make sure the brake cable is routed prop-erly.CAUTION:@Before tightening the wheel a

CHAPTER 3PERIODIC CHECKS AND ADJUSTMENTSINTRODUCTION...3-1

4 - 10CHASREAR WHEEL AND BRAKEEAS00551 REAR WHEEL AND BRAKE123456TR..105 Nm (10.5 m •kg, 75 ft • lb)TR..28 Nm (2.8 m •kg, 20 ft•Ib)TR..13 Nm (1.3 m•kg

4 - 11CHASREAR WHEEL AND BRAKE123450987ALSLSNew6NewTR..7 Nm (0.7 m•kg, 5.1 ft • Ib)Order Job/Part Q’ty RemarksRemoving the rear brake shoe plateRemove

4 - 12CHASREAR WHEEL AND BRAKEEAS00565 CHECKING THE REAR WHEEL1. Check: • rear wheel Refer to “CHECKING THE FRONTWHEEL”.2. Check: •tire • rear wheel D

4 - 13CHASREAR WHEEL AND BRAKE3. Measure: • brake drum inside diameter aOut of specification → Replace the wheel.4. Check: • brake drum inner surface

4 - 14CHASREAR WHEEL AND BRAKEEAS00573 INSTALLING THE BRAKE SHOES1. Install: • brake camshaft lever 1NOTE:@• Align the punch mark a in the brake cam-s

4 - 15CHASFRONT SHOCK ABSORBER ASSEMBLIESEAS00647 FRONT SHOCK ABSORBER ASSEMBLIESOrder Job/Part Q’ty RemarksRemoving the front shock absorberassemblie

4 - 16CHASFRONT SHOCK ABSORBER ASSEMBLIESCHECKING THE FRONT SHOCK ABSORBER ASSEMBLIESThe following procedure applies to both frontshock absorber assem

4 - 17CHASHANDLEBAREAS00664 HANDLEBAROrder Job/Part Q’ty RemarksRemoving the handlebar switches and handlebar gripsRemove the parts in the order liste

4 - 18CHASHANDLEBAROrder Job/Part Q’ty Remarks7 Left handlebar switch 1Refer to “INSTALLING THE HANDLE-BAR”.8 Upper handlebar holder 29 Handlebar 110

4 - 19CHASHANDLEBAREAS00666 REMOVING THE HANDLEBAR1. Stand the scooter on a level surface.WARNING@Securely support the scooter so that thereis no dang