Yamaha Vino YJ50RN Service Manual Download Page 54

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3 - 11

CHK

ADJ

CHECKING THE SPARK PLUG/

MEASURING THE COMPRESSION PRESSURE

4. Check:

• electrodes

Damage/wear

→

Replace the spark plug.

• insulator

Abnormal color

→

Replace the spark plug.

Normal color is medium-to-light tan.

5. Clean:

• spark plug

(with a spark plug cleaner or wire brush)

6. Measure:

• spark plug gap

(with a wire gauge)
Out of specification

→

Regap.

7. Install:

• spark plug

NOTE:

Before installing the spark plug, clean the
spark plug and gasket surface.

8. Connect:

• spark plug cap

Spark plug gap

0.6 ~ 0.7 mm (0.02 ~ 0.03 in)

20 Nm (2.0 m · kg, 14 ft · lb)

EAS00067

MEASURING THE COMPRESSION
PRESSURE

NOTE:

Insufficient compression pressure will result in
a loss of performance.

1. Start the engine, warm it up for several min-

utes, and then turn it off.

2. Remove:

• center cover
• footrest board

Refer to “SIDE COVERS AND FOOTREST
BOARD”.

3. Disconnect:

• spark plug cap

4. Remove:

• spark plug

Summary of Contents for Vino YJ50RN

Page 1: ...YJ50RN SERVICEMANUAL LIT 11616 14 50 5LY 28197 E0 ...

Page 2: ...Yamaha Motor Corporation U S A First edition December 2000 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 P N LIT 11616 14 50 ...

Page 3: ...s models Modifications and significant changes in specifications or procedures will be forwarded to all authorized Yamaha deal ers and will appear in future editions of this manual where applicable NOTE Designs and specifications are subject to change without notice EAS00005 IMPORTANT MANUAL INFORMATION Particularly important information is distinguished in this manual by the following The Safety ...

Page 4: ...of each page except in Chapter 3 PERIODIC CHECKS AND ADJUSTMENTS where the sub section title s appears 3 Sub section titles appear in smaller print than the section title 4 To help identify parts and clarify procedure steps there are exploded diagrams at the start of each removal and disassembly section 5 Numbers are given in the order of the jobs in the exploded diagram A circled number indicates...

Page 5: ...Lubricant B Special tool C Tightening torque D Wear limit clearance E Engine speed F Electrical data Symbols G to L in the exploded diagrams indicate the types of lubricants and lubrication points G Engine oil H Gear oil I Molybdenum disulfide oil J Wheel bearing grease K Lithium soap base grease L Molybdenum disulfide grease Symbols M to N in the exploded diagrams indicate the following M Apply l...

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

Page 7: ...MEMO ...

Page 8: ...PINS 1 2 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 2 CHASSIS SPECIFICATIONS 2 6 ELECTRICAL SPECIFICATIONS 2 9 CONVERSION TABLE 2 11 GENERAL TIGHTENING TORQUE SPECIFICATIONS 2 11 TIGHTENING TORQUES 2 12 ENGINE TIGHTENING TORQUES 2 12 CHASSIS TIGHTENING TORQUES 2 13 LUBRICATION PO...

Page 9: ...OR JOINT 3 17 CHECKING THE FUEL AND VACUUM HOSES 3 17 CHECKING THE CRANKCASE BREATHER HOSE 3 18 CHECKING THE EXHAUST SYSTEM 3 18 CHASSIS 3 19 ADJUSTING THE FRONT BRAKE 3 19 ADJUSTING THE REAR BRAKE 3 19 CHECKING THE BRAKE SHOES 3 20 CHECKING AND ADJUSTING THE STEERING HEAD 3 20 CHECKING THE FRONT SHOCK ABSORBER 3 22 CHECKING THE TIRES 3 22 CHECKING THE WHEELS 3 25 CHECKING AND LUBRICATING THE CABL...

Page 10: ...OES 4 14 INSTALLING THE REAR WHEEL 4 14 FRONT SHOCK ABSORBER ASSEMBLIES 4 15 CHECKING THE FRONT SHOCK ABSORBER ASSEMBLIES 4 16 INSTALLING THE RELAY ARM 4 16 HANDLEBAR 4 17 REMOVING THE HANDLEBAR 4 19 CHECKING THE HANDLEBAR 4 19 INSTALLING THE HANDLEBAR 4 20 STEERING HEAD 4 22 REMOVING THE FORK 4 24 CHECKING THE STEERING HEAD 4 24 INSTALLING THE STEERING HEAD 4 25 REAR SHOCK ABSORBER ASSEMBLY 4 26 ...

Page 11: ...DISASSEMBLING THE SECONDARY PULLEY 5 20 CHECKING THE CLUTCH SHOES 5 20 CHECKING THE SECONDARY PULLEY 5 21 CHECKING THE V BELT 5 22 CHECKING THE PRIMARY PULLEY WEIGHTS 5 22 ASSEMBLING THE SECONDARY PULLEY 5 23 INSTALLING THE PRIMARY PULLEY 5 24 INSTALLING THE BELT DRIVE 5 25 STARTER CLUTCH AND STARTER MOTOR 5 27 CHECKING THE STARTER CLUTCH 5 28 INSTALLING THE STARTER CLUTCH 5 28 TRANSMISSION 5 30 C...

Page 12: ...NG THE CARBURETOR 6 5 INSTALLING THE CARBURETOR 6 6 MEASURING AND ADJUSTING THE FLOAT HEIGHT 6 7 CHECKING THE AUTOCHOKE ASSEMBLY 6 7 CHECKING THE FUEL COCK OPERATION 6 8 CHAPTER 7 ELECTRICAL ELECTRICAL COMPONENTS 7 1 SWITCHES 7 2 CHECKING SWITCH CONTINUITY 7 2 CHECKING THE SWITCHES 7 3 CHECKING THE BULBS AND BULB SOCKETS 7 5 TYPES OF BULBS 7 5 CHECKING THE CONDITION OF THE BULBS 7 6 CHECKING THE C...

Page 13: ... 7 32 AUTO CHOKE SYSTEM 7 39 CIRCUIT DIAGRAM 7 39 TROUBLESHOOTING 7 40 CHAPTER 8 TROUBLESHOOTING STARTING FAILURE HARD STARTING 8 1 ENGINE 8 1 FUEL SYSTEM 8 1 ELECTRICAL SYSTEMS 8 1 INCORRECT ENGINE IDLING SPEED 8 2 ENGINE 8 2 FUEL SYSTEM 8 2 ELECTRICAL SYSTEMS 8 2 POOR MEDIUM AND HIGH SPEED PERFORMANCE 8 2 ENGINE 8 2 FUEL SYSTEM 8 2 FAULTY CLUTCH 8 2 ENGINE OPERATES BUT SCOOTER WILL NOT MOVE 8 2 ...

Page 14: ...LING 8 3 FAULTY LIGHTING OR SIGNALING SYSTEM 8 4 HEADLIGHT DOES NOT LIGHT 8 4 HEADLIGHT BULB BURNT OUT 8 4 TAIL BRAKE LIGHT DOES NOT LIGHT 8 4 TAIL BRAKE LIGHT BULB BURNT OUT 8 4 TURN SIGNAL DOES NOT LIGHT 8 4 TURN SIGNAL BLINKS SLOWLY 8 4 TURN SIGNAL REMAINS LIT 8 4 TURN SIGNAL BLINKS QUICKLY 8 4 HORN DOES NOT SOUND 8 4 ...

Page 15: ...NUMBER The vehicle identification number 1 is stamped into the frame 1 EAS00018 MODEL CODE The model code label 1 is affixed to the loca tion shown in the figure Record the informa tion on this label in the space provided This information will be needed to order spare parts SCOOTER IDENTIFICATION 1 ...

Page 16: ...for the correct installation of all parts 5 Keep all parts away from any source of fire EAS00021 REPLACEMENT PARTS 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 inferior in quality EAS00022 GASKETS OIL SEALS AND O RINGS 1 When overhauling the engine replace all gaskets...

Page 17: ...l 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 EAS00025 CIRCLIPS Before reassembly check all circlips carefully and replace damaged or distorted circlips Always replace piston pin clips after one use When installing a circlip 1 make sure the sharp edged corner 2 is positione...

Page 18: ...nd disconnect 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 revi...

Page 19: ...al guide This tool is used to install oil seals YM 01411 Crankshaft installer spacer This tool is used to install the crank shaft YM 34487 Dynamic spark tester This tool is used to check the ignition system components YS 28891 Clutch spring holder This tool is used to disassembly and assembly the secondary pulley YU 01135 Crankcase separating tool This tool is used to remove the crank shaft and to...

Page 20: ...he steering stem ring nut YU 8036 A Inductive tachometer This tool is used to check engine speed Crankshaft installer tool set YU 90050 Crankshaft installer pot YU 90058 Crankshaft installer bolt YU 90060 Crankshaft installer tool set Crankshaft installer pot Crankshaft installer bolt These tools are used to install the crankshaft YU 90062 Crankshaft installer adaptor M10 This tool is used to inst...

Page 21: ...1 7 GEN INFO ACC 1100 15 01 Quick Gasket This sealant is used to seal to mating surfaces e g crankcase mating sur faces Tool No Tool name Function Illustration SPECIAL TOOLS 1 ...

Page 22: ...erall length 1 630 mm 64 1 in Overall width 630 mm 24 8 in Overall height 1 030 mm 40 5 in Seat height 715 mm 28 1 in Wheelbase 1 150 mm 45 3 in Minimum ground clearance 85 mm 3 3 in Minimum turning radius 1 600 mm 63 in Weight Wet with oil and a full fuel tank 74 kg 163 lb GENERAL SPECIFICATIONS ...

Page 23: ...cycle oil or 2 stroke engine oil Quantity Capacity 1 4 L 1 23 Imp qt 1 48 US qt Air filter oil grade Foam air filter oil or SAE 10W30SE Transmission Recommended oil Yamalube 4 10W30 or SAE 10W30 type SE motor oil Periodic oil change 0 1 L 0 09 Imp qt 0 11 US qt Total amount 0 11 L 0 1 Imp qt 0 12 US qt Starting system type Electric and kick starter Spark plug Model manufacturer quantity BPR7HS NGK...

Page 24: ...935 0 3937 in 9 976 mm 0 3928 in Piston pin to piston pin bore clear ance 0 004 0 019 mm 0 00016 0 00075 in 0 069 mm 0 0027 in Piston ring Top ring Ring type Keystone Dimensions B T 1 2 1 8 mm 0 05 0 07 in End gap installed 0 15 0 35 mm 0 006 0 014 in 0 70 mm 0 028 in Ring side clearance 0 03 0 05 mm 0 0012 0 0020 in 0 10 mm 0 0039 in 2nd ring Ring type Keystone Dimensions B T 1 2 1 8 mm 0 05 0 07...

Page 25: ...atic Clutch shoe Thickness 4 0 mm 0 157 in 1 0 mm 0 039 in Clutch shoe spring Free length 29 9 mm 1 18 in Kickstarter Kickstarter type Ratchet Kickstarter pinion gear clip force 0 15 0 25 kg 0 34 0 56 lb Transmission Transmission type V belt automatic Primary reduction system Helical Primary reduction ratio 48 13 3 692 Secondary reduction system Spur gear Secondary reduction ratio 42 13 3 231 Oper...

Page 26: ...0 Jet needle 3SOC 3 5 Needle jet 2 090 Cutaway 2 5 Pilot jet 46 Bypass 1 0 8 Valve seat size 1 8 Starter jet 1 46 Float height 15 17 mm 0 59 0 67 in Reed valve Thickness 0 164 0 176 mm 0 0065 0 0069 in Valve stopper height 7 0 7 4 mm 0 28 0 29 in Valve bending limit 0 2 mm 0 008 in Autolube pump Plunger diameter 2 62 mm 0 103 in Minimum stroke 0 1 mm 0 0039 in Maximum stroke 0 49 mm 0 0193 in Item...

Page 27: ... Panel wheel Rim Size 10 2 15 Material Steel Wheel travel 46 mm 1 81 in Wheel runout Max radial wheel runout 1 0 mm 0 04 in Max lateral wheel runout 1 0 mm 0 04 in Front tire Tire type Tubeless Size 80 90 10 34J Model manufacturer MB38 C 922 INOUE CHENG SHIN Tire pressure cold 0 90 kg 0 198 lb 150 kPa 1 50 kg cm2 21 8 psi Min tire tread depth 1 0 mm 0 04 in Rear tire Tire type Tubeless Size 80 90 ...

Page 28: ...ing Brake drum inside diameter 110 mm 4 33 in 110 5 mm 4 35 in Lining thickness 4 mm 0 16 in 2 mm 0 08 in Front suspension Suspension type Bottom link fork Front fork type Coil spring oil damper Front fork travel 40 mm 1 57 in Spring Free length 156 5 mm 6 16 in 153 4 mm 6 04 in Spring rate K1 12 8 N mm 1 28 kgf mm 73 09 lb in Spring stroke K1 0 20 mm 0 0 79 in Spring rate K2 30 4 N mm 3 04 kgf mm...

Page 29: ...bly type Coil spring oil damper Rear shock absorber assembly travel 45 mm 1 77 in Spring Free length 173 5 mm 6 83 in 170 0 mm 6 69 in Installed length 166 5 mm 6 56 in Spring rate K1 34 5 N mm 3 45 kgf mm 197 lb in Spring stroke K1 0 45 mm 0 1 77 in Optional spring available No Item Standard Limit 2 ...

Page 30: ...stance W B 0 29 0 43 Ω Voltage regulator Regulator type Semiconductor short circuit Model manufacturer SH671 12 SHINDENGEN No load regulated voltage DC 14 0 15 0 V No load regulated voltage AC 12 3 13 3 V Rectifier Model manufacturer SH671 12 SHINDENGEN Rectifier capacity DC 8 A Rectifier capacity AC 12 A Withstand voltage 200 V Battery Battery type GT4B 5 Battery voltage capacity 12 V 2 5 AH Spec...

Page 31: ...er G8MS 1A48T L3 Y28 OMRON Amperage 20 A Coil resistance 54 66 Ω Horn Horn type Plane Model manufacturer quantity GF 12 NIKKO 1 Max amperage 1 5 A Performance 95 115 db 2 m Coil resistance 4 3 4 8 Ω Turn signal relay Relay type Condenser Model manufacturer FZ222SD DENSO Self cancelling device built in No Turn signal blinking frequency 75 95 cycles min Wattage 10 W 2 3 4 W Oil level gauge model man...

Page 32: ... specified tightening torque specifications require clean dry threads Com ponents should be at room temperature A Width across flats B Thread diameter Ex METRIC MULTIPLIER IMPERIAL mm 0 03937 in 2 mm 0 03937 0 08 in METRIC TO IMPERIAL Tighten ing 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 03527 lb oz Spee...

Page 33: ...ght crankcase Screw M6 6 9 0 9 6 5 Bearing retainer right crankcase Screw M6 1 7 0 7 5 1 Transmission cover Screw M6 5 9 0 9 6 5 Sheave cover Screw M6 10 9 0 9 6 5 Air filter case Screw M6 2 9 0 9 6 5 Starter motor ground lead Screw M6 1 7 0 7 5 1 Transmission oil drain bolt Bolt M8 1 18 1 8 13 Oil filler plug M14 1 3 0 3 2 2 Idle gear plate Screw M6 2 8 0 8 5 8 Kickstarter crank Bolt M6 1 11 1 1 ...

Page 34: ...lower M8 19 1 9 13 Front turn signal light M12 7 0 7 5 1 Fuel tank upper M6 7 0 7 5 1 Fuel tank lower M6 10 1 0 7 2 Fuel sender and fuel tank M5 3 0 3 2 2 Seat lock assembly M6 7 0 7 5 1 Carrier upper M6 10 1 0 7 2 Carrier lower M8 15 1 5 11 Storage box M6 8 0 8 5 8 License plate bracket and rear turn signal bracket M6 12 1 2 8 7 Rear turn signal bracket and tail brake light M6 7 0 7 5 1 Tail cove...

Page 35: ...l Oil seal lips LS O rings LS Bearings E Piston surface E Piston pin E Cylinder E Transmission case bearing LT Right crankcase bearing retainer LT Autolube pump LS Starter wheel gear LS Idle gear plate M Secondary drive gear G Kickstarter pinion gear LS Drive axle M Pump drive gear LS Main axle G Main axle bearing G 2 ...

Page 36: ...al lips LS O rings LS Bearings LS Speedometer drive gear LS Front brake camshaft LS Front brake cable LS Throttle cable LS Tube guide throttle grip inner surface LS Upper steering stem ring nut LS Upper bearing outer race LS Lower bearing outer race LS Rear brake camshaft LS Centerstand LS ...

Page 37: ... Main switch 9 Fuel gauge 0 Speedometer cable È Push the brake cable flange in until it contacts the lever holder É Fasten the handlebar switch leads brake light switch leads meter light lead speedometer cable brake cables and throttle cable with a plastic locking tie Ê Pass the left handlebar switch lead front brake light switch lead and throttle cable over the cable guide 2 ...

Page 38: ...8 Speedometer cable 9 Battery 0 Rectifier regulator coupler A CDI unit lead coupler B Fuel overflow hose C Crankcase breather hose D Ground lead E Carburetor overflow hose F Rear brake cable G Throttle cable È Fasten the turn signal light leads with the clamp É Pass the front turn signal light leads headlight coupler and horn lead through the hole of the front turn signal light bracket ...

Page 39: ...ch leads and brake light switch leads with a plastic band Í Pass the vacuum hose and fuel hose through the holder Be sure to pass the vacuum hose through the holder first Î Install the fuel tank so that the paint mark on the fuel hose is facing up Ï Pass the fuel overflow hose through the guide Ð Pass the crankcase breather hose between the crankcase and rear brake cable Ñ Pass the carburetor over...

Page 40: ... Battery leads 4 Battery 5 Starter motor coupler 6 AC magneto coupler 7 Auto choke coupler 8 Headlight coupler 9 Front turn signal leads 0 Horn lead A Main switch lead B Flasher relay lead C Ignition coil lead D Spark plug lead E Oil hose F Rear turn signal leads G Wire harness ...

Page 41: ...tic locking tie Ê Fasten the main switch lead with a plastic lock ing tie Ë Fasten the wire harness with a plastic locking tie Ì Pass the wire harness on the inside of the seat bracket Í Pass one end of a plastic clip through the hole of the fuel tank flange and then fasten the tail brake light lead and rear turn signal light leads with the clip 2 ...

Page 42: ...y 4 Starter relay 5 Oil hose 6 Oil level switch lead 7 AC magneto lead 8 Fuel sender lead 9 Tail brake light lead 0 Rear turn signal leads A CDI unit B Vacuum hose C Rectifier regulator D Fuel hose E Auto choke lead F Oil delivery hose G Throttle cable H Tail brake light ...

Page 43: ...ine bracket and engine mount spacer and then through the hole of the cover Ë Fasten the wire harness with a plastic locking tie in front of the storage box bracket Ì Fasten the auto choke lead with a plastic clip Í After connecting the AC magneto coupler and starter motor coupler cover the couplers with the coupler cover Î Pass the rear brake cable through the bottom cowling guide Ï To rear turn s...

Page 44: ... Clean Replace if necessary 3 Carburetor Check idle speed Adjust if necessary 4 Fuel line Check fuel hose and vacuum hose for cracks or damage Replace if necessary 5 Final gear oil Check oil leakage Correct if necessary Replace every 8 000 mi 12 000 km or 24 months Ride scooter a few minutes before draining REPLACE 6 Autolube pump Check operation Correct if necessary Bleed 7 Brakes Check operation...

Page 45: ...needs more frequent service if you are riding in unusually wet or dusty areas EAU03903 NOTE From 6 000 mi 9 000 km or 18 months repeat the maintenance intervals starting from 2 000 mi 3 000 km or 6 months PERIODIC MAINTENANCE AND LUBRICATION 3 ...

Page 46: ...R 7 Nm 0 7 m kg 5 1 ft Ib T R 12 Nm 1 2 m kg 8 7 ft Ib 11 Order Job Part Q ty Remarks Removing the side covers and foot rest board Remove the parts in the order listed 1 Seat 1 2 Pin 1 3 Seat bracket 1 4 Carrier 1 5 Center cover 1 6 Oil tank cover 1 7 Cowling bold cap 2 8 Side cover left 1 9 Side cover right 1 10 Tail brake light coupler 1 Disconnect 11 Rear turn signal lead 4 Disconnect ...

Page 47: ...10 Nm 1 0 m kg 7 2 ft Ib T R 7 Nm 0 7 m kg 5 1 ft Ib T R 12 Nm 1 2 m kg 8 7 ft Ib 11 Order Job Part Q ty Remarks 12 Rear turn signal bracket 1 13 Rear turn signal left 1 14 Rear turn signal right 1 15 Tail brake light 1 16 Fuel tank cap 1 17 Tail cover 1 18 Footrest board 1 For installation reverse the removal procedure 3 ...

Page 48: ... shield Remove the parts in the order listed Footrest board Refer to SIDE COVERS AND FOOT REST BOARD 1 Headlight cover 1 2 Headlight coupler 1 Disconnect 3 Front turn signal lead 4 Disconnect 4 Horn lead 2 Disconnect 5 Front turn signal bracket 1 6 Horn 1 7 Front turn signal left 1 8 Front turn signal right 1 9 Front panel 1 10 Fuel level gauge coupler 1 Disconnect ...

Page 49: ...6 CHK ADJ FRONT PANEL AND LEG SHIELD 1 9 2 3 4 5 7 13 6 8 10 11 12 Order Job Part Q ty Remarks 11 Fuel level gauge 1 12 Main switch cover 1 13 Leg shield 1 For installation reverse the removal procedure 3 ...

Page 50: ...up for sev eral minutes 2 Remove center cover Refer to SIDE COVERS AND FOOTREST BOARD 3 Attach inductive tachometer 1 onto the spark plug lead of cylinder 4 Measure engine idling speed Out of specification Adjust Inductive tachometer YU 8036 A Engine idling speed 1 800 r min 1 5 Adjust engine idling speed a Turn the throttle stop screw 1 in direction a or b until the specified engine idling speed ...

Page 51: ...ttle cable free play a Out of specification Adjust 2 Adjust throttle cable free play a Loosen the locknut 1 b Turn the adjusting nut 2 in direction a or b until the specified throttle cable free play is obtained c Tighten the locknut WARNING After adjusting the throttle cable free play start the engine and turn the handlebar to the right and to the left to ensure that this does not cause the engin...

Page 52: ... side cover right footrest board Refer to SIDE COVERS AND FOOTREST BOARD air shroud Refer to GENERATOR in chapter 5 2 Check oil level Refer to CHECKING THE ENGINE OIL LEVEL 3 Fill oil tank 1 oil tank filler cap 2 Recommended oil Yamalube 2 cycle oil or 2 stroke engine oil 4 Bleed pump case and or oil hose a Remove the bleed screw 1 b Keep the oil running out until air bubbles disappear c When air ...

Page 53: ...er right center cover Refer to SIDE COVERS AND FOOTREST BOARD EAS00060 CHECKING THE SPARK PLUG 1 Disconnect spark plug cap 2 Remove spark plug CAUTION Before removing the spark plug blow away any dirt accumulated in the spark plug well with compressed air to prevent it from fall ing into the cylinder 3 Check spark plug type Incorrect Change Spark plug type manufacturer BPR7HS NGK BLEEDING THE AUTO...

Page 54: ...specification Regap 7 Install spark plug NOTE Before installing the spark plug clean the spark plug and gasket surface 8 Connect spark plug cap Spark plug gap 0 6 0 7 mm 0 02 0 03 in T R 20 Nm 2 0 m kg 14 ft lb EAS00067 MEASURING THE COMPRESSION PRESSURE NOTE Insufficient compression pressure will result in a loss of performance 1 Start the engine warm it up for several min utes and then turn it o...

Page 55: ... to steps c and d a Set the main switch to ON b With the throttle wide open crank the engine until the reading on the compression gauge stabilizes WARNING To prevent sparking ground the spark plug lead before cranking the engine c If the compression pressure is above the maximum specification check the cylinder head and piston crown for carbon deposits Carbon deposits Eliminate Compression pressur...

Page 56: ... cap Compression pressure with oil applied into the cylinder Reading Diagnosis Higher than with out oil Piston wear or damage Repair Same as without oil Piston ring s cyl inder head gasket or piston possibly defective Repair T R 20 Nm 2 0 m kg 14 ft lb EAS00072 CHECKING THE ENGINE OIL LEVEL 1 Stand the scooter on a level surface NOTE Place the scooter on a suitable stand Make sure the scooter is u...

Page 57: ...2 cycle oil or 2 stroke engine oil REPLACING THE TRANSMISSION OIL 1 Stand the scooter on a level surface NOTE Place the scooter on a suitable stand Make sure the scooter is upright 2 Start the engine warm it up for several min utes and then turn it off 3 Place a container under the transmission oil drain bolt 4 Remove oil filler plug 1 O ring 2 1 1 2 CHECKING THE ENGINE OIL LEVEL REPLACING THE TRA...

Page 58: ...eck O ring Damage Replace 8 Install gasket 1 transmission oil drain bolt 2 New 1 2 New T R 18 Nm 1 8 m kg 13 ft lb 9 Fill crankcase with the specified amount of the recom mended transmission oil Recommended oil SAE 10W30SE Total amount 0 11 L 0 1 Imp qt 0 12 US qt 10 Install O ring oil filler plug REPLACING THE TRANSMISSION OIL ...

Page 59: ...th solvent WARNING Never use low flash point solvents such as gasoline to clean the air filter element Such solvents may cause a fire or an explo sion NOTE After cleaning gently squeeze the air filter ele ment to remove the excess solvent CAUTION Do not twist the air filter element when squeezing it 4 Check air filter element 1 Damage Replace 5 Apply the recommended oil to the entire surface of th...

Page 60: ...eading to poor engine performance and possible overheat ing 7 Install footrest board Refer to SIDE COVERS AND FOOTREST BOARD EAS00094 CHECKING THE CARBURETOR JOINT 1 Remove center cover footrest board Refer to SIDE COVERS AND FOOTREST BOARD air filter case 2 Check carburetor joint 1 Cracks damage Replace Refer to CARBURETOR in chapter 6 3 Install air filter case footrest board center cover Refer t...

Page 61: ...ATHER HOSE 1 Check crankcase breather hose 1 Cracks damage Replace Loose connection Connect properly CAUTION Make sure the crankcase breather hose is routed correctly EAS00099 CHECKING THE EXHAUST SYSTEM The following procedure applies to all of the exhaust pipes and gaskets 1 Check exhaust pipe muffler 1 Cracks damage Replace gasket 2 Exhaust gas leaks Replace 2 Check tightening torque T R Exhaus...

Page 62: ...Adjust brake lever free play a Turn the adjusting nut 1 in direction a or b until the specified brake lever free play is obtained CAUTION After adjusting the brake lever free play make sure there is no brake drag Direction a Brake lever free play is increased Direction b Brake lever free play is decreased EAS00114 ADJUSTING THE REAR BRAKE 1 Check brake lever free play a Out of specification Adjust...

Page 63: ...drag Direction a Brake lever free play is increased Direction b Brake lever free play is decreased EAS00127 CHECKING THE BRAKE SHOES 1 Operate the brake 2 Check wear indicator 1 Reaches the wear limit line 2 Replace the brake shoes as a set Refer to FRONT WHEEL AND BRAKE and REAR WHEEL AND BRAKE in chap ter 4 È Front brake É Rear brake È É EAS00148 CHECKING AND ADJUSTING THE STEERING HEAD 1 Stand ...

Page 64: ...ve the upper steering stem ring nut b Loosen the upper race 1 and then tighten it to specification with the steering nut wrench 45 mm 2 NOTE Set the torque wrench at a right angle to the steering stem ring nut wrench c Hold the upper race with a steering nut wrench 45 mm and tighten the upper steer ing stem ring nut 3 with a steering nut wrench 4 d Check the steering head for looseness or binding ...

Page 65: ... ABSORBER 1 Stand the scooter on a level surface WARNING Securely support the scooter so that there is no danger of it falling over 2 Hold the scooter upright and apply the front brake 3 Check front shock absorber operation Push down hard on the handlebar several times and check if the front fork rebounds smoothly Rough movement Repair Refer to FRONT SHOCK ABSORBER ASSEMBLIES in chapter 4 EAS00163...

Page 66: ... could cause tire damage an accident or an injury NEVER OVERLOAD THE SCOOTER total of cargo rider and accessories WARNING It is dangerous to ride with a worn out tire When the tire tread reaches the wear limit replace the tire immediately Basicweight with oil and a full fuel tank 74 kg 163 lb Maximum load 76 kg 168 lb Cold tire pressure Front Rear 150 kPa 1 50 kgf cm2 21 8 psi 175 kPa 1 75 kgf cm2...

Page 67: ... it is absolutely necessary to do so use great care and replace the tube as soon as possible with a good quality replacement È Tire É Wheel After extensive tests the tires listed below have been approved by Yamaha Motor Co Ltd for this model The front and rear tires should always be by the same manufacturer and of the same design No guarantee concerning han dling characteristics can be given if a ...

Page 68: ...rection of rotation mark 1 Install the tire with the mark pointing in the direction of wheel rotation Align the mark 2 with the valve installation point Manufacturer Model Size INOUE MB38 80 90 10 34J CHENG SHIN C 922 80 90 10 34J EAS00168 CHECKING THE WHEELS The following procedure applies to both of the wheels 1 Check wheel Damage out of round Replace WARNING Never attempt to make any repairs to...

Page 69: ...ble sheath Damage Replace 2 Check cable operation Rough movement Lubricate NOTE Hold the cable end upright and pour a few drops of lubricant into the cable sheath or use a suitable lubricating device Recommended lubricant Engine oil or a suitable cable lubricant EAS00171 LUBRICATING THE LEVERS Lubricate the pivoting point and metal to metal moving parts of the levers Recommended lubricant Lithium ...

Page 70: ...S 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 milk of magnesia beaten egg or vegetable oil Get immediate medi...

Page 71: ...INE REMOVAL in chapter 5 2 Disconnect battery lead coupler 1 from the battery terminals NOTE Push down on the tab a and then remove the battery lead coupler 3 Remove battery 1 4 Measure battery charge a Connect a battery tester 1 to the battery terminals NOTE The charge state of an MF battery can be checked by measuring its open circuit volt age i e the voltage when the positive termi nal is disco...

Page 72: ... to regulate the charging current on the battery charger be careful not to overcharge the battery When charging a battery be sure to remove it from the scooter If charging has to be done with the battery mounted on the scooter disconnect the negative battery lead from the battery terminal To reduce the chance of sparks do not plug in the battery charger until the bat tery charger leads are connect...

Page 73: ...t the battery charger and let the battery cool before reconnecting it Hot batteries can explode As shown in the following illustration the open circuit voltage of an MF battery sta bilizes about 30 minutes after charging has been completed Therefore wait 30 minutes after charging is completed before measuring the open circuit volt age 3 ...

Page 74: ...3 31 CHK ADJ Charging method using a variable voltage charger CHECKING AND CHARGING THE BATTERY ...

Page 75: ...3 32 CHK ADJ Charging method using a constant voltage charger CHECKING AND CHARGING THE BATTERY 3 ...

Page 76: ...battery terminals Dirt Clean with a wire brush Loose connection Connect properly 9 Lubricate battery terminal 10 Install battery box Refer to ENGINE REMOVAL in chapter 5 center cover Refer to SIDE COVERS AND FOOTREST BOARD Recommended lubricant Dielectric grease CHECKING AND CHARGING THE BATTERY ...

Page 77: ... continuity 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 YU 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 operational d If the fuse immediately blows again c...

Page 78: ... could possibly cause a fire 4 Install battery Refer to ENGINE REMOVAL in chapter 4 center cover Refer to SIDE COVERS AND FOOTREST BOARD EAS00182 REPLACING THE HEADLIGHT BULB 1 Remove Headlight cover Refer to FRONT PANEL AND LEG SHIELD 2 Disconnect headlight coupler 1 3 Remove headlight bulb holder cover 2 4 Detach headlight bulb holder 1 5 Remove headlight bulb 2 WARNING Since the headlight bulb ...

Page 79: ...l be adversely affected If the headlight bulb gets soiled thoroughly clean it with a cloth moistened with alcohol or lacquer thinner 7 Attach headlight bulb holder 8 Install headlight bulb holder cover 9 Connect headlight coupler 10 Install Headlight cover Refer to FRONT PANEL AND LEG SHILD New EAS00184 ADJUSTING THE HEADLIGHT BEAM 1 Adjust headlight beam vertically a Loosen the adjusting screw 1 ...

Page 80: ... ADJ ADJUSTING THE HEADLIGHT BEAM 2 Adjust headlight beam horizontally a Turn the adjusting knob 2 in direction a or b Direction a Headlight beam moves to the right Direction b Headlight beam moves to the left ...

Page 81: ...the front wheel and brake Remove the parts in the order listed NOTE Place the scooter on a suitable stand so that the front wheel is elevated 1 Speedometer cable assembly 1 2 Adjusting nut 1 Refer to INSTALLING THE FRONT WHEEL 3 Front brake cable 1 4 Pin 1 5 Axle nut 1 6 Wheel axle 1 7 Front wheel assembly 1 FRONT WHEEL AND BRAKE 4 ...

Page 82: ...4 2 CHAS FRONT WHEEL AND BRAKE 6 9 7 3 4 2 8 1 5 T R 48 Nm 4 8 m kg 35 ft Ib Order Job Part Q ty Remarks 8 Front brake shoe plate 1 9 Spacer 1 For installation reverse the removal procedure ...

Page 83: ... Part Q ty Remarks Disassembling the front wheel Remove the parts in the order listed 1 Oil seal 1 Refer to CHECKING THE FRONT WHEEL 2 Wheel bearing right 1 3 Spacer 1 4 Collar 1 5 Wheel bearing left 1 6 Dust seal 1 For assembly reverse the disassembly procedure 4 ...

Page 84: ...front brake shoe plate Remove the parts in the order listed 1 Brake shoe 2 2 Brake shoe spring pin side 1 3 Brake shoe spring brake camshaft side 1 4 Bushing 1 5 Speedometer drive gear 1 6 Brake camshaft lever 1 7 Brake shoe wear indicator 1 8 Spring 1 9 Brake camshaft 1 0 Oil seal 1 A O ring 1 For assembly reverse the disassembly procedure ...

Page 85: ...eck tire front wheel Damage wear Replace Refer to CHECKING THE TIRES and CHECKING THE WHEELS in chapter 3 3 Measure radial wheel runout 1 lateral wheel runout 2 Over the specified limits Replace Radial wheel runout limit 1 0 mm 0 04 in Lateral wheel runout limit 1 0 mm 0 04 in 4 Check wheel bearings Front wheel turns roughly or is loose Replace the wheel bearings oil seal Damage wear Replace 4 ...

Page 86: ...e c Remove the wheel bearings 3 with a gen eral bearing puller d Install the new wheel bearings and oil seal in the reverse order of disassembly CAUTION Do not contact the wheel bearing inner race 4 or balls 5 Contact should be made only with the outer race 6 NOTE Use a socket 7 that matches the diameter of the wheel bearing outer race and oil seal 1 2 New New EAS00535 CHECKING THE SPEEDOMETER GEA...

Page 87: ... Do not allow oil or grease to contact the brake shoes NOTE Replace the brake shoes as a set if either is worn to the wear limit Brake shoe lining thickness limit minimum 2 mm 0 08 in 3 Measure brake drum inside diameter a Out of specification Replace the wheel 4 Check brake drum inner surface Oil deposits Clean Remove the oil with a rag soaked in lacquer thinner or solvent Scratches Repair Lightl...

Page 88: ...shown c Check that the brake shoes are properly positioned 2 Install speedometer drive gear bushing 3 1 2 EAS00540 INSTALLING THE FRONT WHEEL 1 Lubricate wheel axle wheel bearings oil seal lips speedometer drive gear Recommended lubricant Lithium soap base grease 2 Install brake shoe plate 1 Align the tabs on the wheel hub with the slit between the speedometer drive gear and the bushing 3 Install ...

Page 89: ...ten wheel axle nut WARNING Make sure the brake cable is routed prop erly CAUTION Before tightening the wheel axle nut push down hard on the handlebar several times and check if the front fork rebounds smoothly T R 48 Nm 4 8 m kg 35 ft lb 4 ...

Page 90: ...13 Nm 1 3 m kg 9 4 ft Ib New Order Job Part Q ty Remarks Removing the rear wheel and brake Remove the parts in the order listed NOTE Place the scooter on a suitable stand so that the rear wheel is elevated 1 Muffler 1 2 Gasket 1 3 Axle nut 1 4 Rear wheel assembly 1 5 Washer 1 6 Dust seal 1 For installation reverse the removal procedure ...

Page 91: ...rear brake shoe plate Remove the parts in the order listed 1 Adjusting nut 1 2 Rear brake cable 1 3 Pin 1 4 Brake shoe 2 5 Brake shoe spring pin side 1 6 Brake shoe spring brake camshaft side 1 7 Brake camshaft lever 1 8 Brake shoe wear indicator 1 9 Spring 1 0 Brake camshaft 1 A O ring 2 For installation reverse the removal procedure 4 ...

Page 92: ...EL EAS00569 CHECKING THE BRAKE The following procedure applies to all of the brake shoes 1 Check brake shoe lining Glazed areas Repair Sand the glazed areas with course sandpa per NOTE After sanding the glazed areas clean the brake shoe with a cloth 2 Measure brake shoe lining thickness a Out of specification Replace WARNING Do not allow oil or grease to contact the brake shoes NOTE Replace the br...

Page 93: ... the scratches with an emery cloth 5 Check brake camshaft Damage wear Replace Brake drum inside diameter limit maximum 110 5 mm 4 35 in EAS00570 INSTALLING THE BRAKE SHOE PLATE 1 Install brake camshaft 1 spring brake shoe wear indicator 2 a Align the projection a on the brake shoe wear indicator with the notch in the brake shoe camshaft b Install the brake camshaft so its punch mark is positioned ...

Page 94: ...ap base grease WARNING After installing the rear brake camshaft remove any excess grease 2 Install brake shoes NOTE Do not to damage the springs during installa tion 1 INSTALLING THE REAR WHEEL 1 Tighten wheel axle nut CAUTION Do not loosen the wheel axle nut after tight ening it to the specified torque 2 Install rear brake cable adjuster 3 Adjust brake lever free play Refer to ADJUSTING THE REAR ...

Page 95: ...ove the parts in the order listed The following procedure applies to both of the front shock absorbers Front panel Refer to FRONT PANEL AND LEG SHIELD in chapter 3 Front wheel Refer to FRONT WHEEL AND BRAKE 1 Relay arm cover 2 2 Front fender 1 3 Relay arm assembly 2 4 Front shock absorber assembly left right 2 For installation reverse the removal procedure 4 ...

Page 96: ...1 Check front shock absorber rod Bends damage Replace the front shock absorber assembly front shock absorber Oil leaks Replace the front shock absorber assembly spring Damage wear Replace the front shock absorber assembly bolt Bends damage wear Replace INSTALLING THE RELAY ARM 1 Install metal spacer 1 oil seal 2 bushing 3 spacer 4 LS LS 2 1 2 4 3 New New New ...

Page 97: ...r switches and handlebar grips Remove the parts in the order listed Center cover Refer to SIDE COVERS AND FOOT REST BOARD in chapter 3 1 Rear view mirror left right 2 2 Front brake cable 1 3 Rear brake cable 1 4 Throttle cable holder 1 Loosen 5 Right handlebar switch 1 6 Throttle grip 1 4 ...

Page 98: ...r Job Part Q ty Remarks 7 Left handlebar switch 1 Refer to INSTALLING THE HANDLE BAR 8 Upper handlebar holder 2 9 Handlebar 1 10 Handlebar grip 1 Refer to REMOVING THE HANDLE BAR For installation reverse the removal procedure ...

Page 99: ...and the scooter on a level surface WARNING Securely support the scooter so that there is no danger of it falling over 2 Check handlebar 1 Bends cracks damage Replace WARNING Do not attempt to straighten a bent handle bar as this may dangerously weaken it 3 Install handlebar grip a Apply a thin coat of rubber adhesive onto the left end of the handlebar b Slide the handlebar grip over the left end o...

Page 100: ...ON First tighten the bolts on the front side of the handlebar holder and then on the rear side NOTE Install the upper handlebar holders with the grooves a facing inward Align the match marks b on the handlebar with the upper surface of the lower handlebar holder 1 2 T R 10 Nm 1 0 m kg 7 2 ft lb 3 Install left handlebar switch 1 NOTE Align the mating surfaces of the left handlebar switch with the p...

Page 101: ...dlebar 5 Install right handlebar switch 1 WARNING Make sure the throttle grip operates smoothly NOTE Align the mating surfaces of the right handle bar switch with the punch mark a on the han dlebar 6 Adjust throttle cable free play Refer to ADJUSTING THE THROTTLE CABLE FREE PLAY in chapter 3 Throttle cable free play at the flange of the throttle grip 1 5 3 5 mm 0 06 0 14 in 1 4 ...

Page 102: ...hapter 3 Front panel leg shield Refer to FRONT PANEL AND LEG SHIELD in chapter 3 Front shock absorber assemblies Refer to FRONT SHOCK ABSORBER ASSEMBLIES Handlebar Refer to HANDLEBAR 1 Meter light lead coupler 1 Disconnect 2 Speedometer assembly 1 3 Speedometer cable 1 4 Lower handlebar holder cover 1 5 Rubber cover 1 6 Lower handlebar holder bracket 1 For installation reverse the removal procedur...

Page 103: ...ing the fork Remove the parts in the order listed 1 Cover 1 2 Upper steering stem ring nut 1 3 Upper race 1 4 Fork 1 5 Upper bearing 1 6 Lower bearing 1 7 Upper bearing outer race 1 8 Lower bearing outer race 1 For installation reverse the removal procedure 4 ...

Page 104: ...upper race with the steering nut wrench 45 mm and then remove the upper steering stem ring nut with the steering nut wrench WARNING Securely support the lower bracket so that there is no danger of it falling Steering nut wrench YU 33975 Steering nut wrench 45 mm YU 01444 1 2 EAS00681 CHECKING THE STEERING HEAD 1 Wash bearings bearing races Recommended cleaning solvent Kerosene 2 Check bearings 1 b...

Page 105: ...bearing races as a set Whenever the steering head is disassem bled replace the rubber seal 4 Check upper bracket lower bracket along with the steering stem Bends cracks damage Replace EAS00684 INSTALLING THE STEERING HEAD 1 Lubricate upper bearing lower bearing bearing races Recommended lubricant Lithium soap base grease 2 Install upper race 1 upper steering stem ring nut 2 Refer to CHECKING AND A...

Page 106: ... 22 ft Ib T R 15 Nm 1 5 m kg 11 ft Ib 1 Order Job Part Q ty Remarks Removing the rear shock absorber assembly Remove the parts in the order listed Side cover left Refer to SIDE COVERS AND FOOT REST BOARD in chapter 3 1 Rear shock absorber assembly 1 For installation reverse the removal procedure ...

Page 107: ...RBER ASSEMBLY 1 Check rear shock absorber rod Bends damage Replace the rear shock absorber assembly rear shock absorber Oil leaks Replace the rear shock absorber assembly spring Damage wear Replace the rear shock absorber assembly bolts Bends damage wear Replace EAS00697 INSTALLING THE REAR SHOCK ABSORBER ASSEMBLY 1 Install rear shock absorber assembly rear shock absorber assembly upper nut rear s...

Page 108: ...ty Remarks Removing the engine Remove the parts in the order listed Center cover side cover left right and footrest board Refer to SIDE COVERS AND FOOT REST BOARD in chapter 3 Carburetor Refer to CARBURETOR in chapter 6 1 Muffler 1 2 Coupler cover 1 3 Stator coil coupler 1 Disconnect 4 Starter motor coupler 1 Disconnect 5 Starter relay coupler 1 Disconnect 6 Battery 1 7 Battery box 1 8 Oil hose 1 ...

Page 109: ... Nm 2 8 m kg 20 ft Ib T R 11 Nm 1 1 m kg 8 0 ft Ib T R 13 Nm 1 3 m kg 9 4 ft Ib 1 New Order Job Part Q ty Remarks 10 Adjusting nut 1 11 Rear brake cable 1 12 Pin 1 13 Kickstarter crank 1 14 Bolt rear shock absorber lower 1 15 Engine mounting bolt nut 1 1 16 Engine assembly 1 For installation reverse the removal procedure 5 ...

Page 110: ...l engine mounting bolt nut 1 bolt rear shock absorber lower 2 2 Install kickstarter crank muffler bolts exhaust pipe bolts T R 84 Nm 8 4 m kg 61 ft lb T R 15 Nm 1 5 m kg 11 ft lb T R 11 Nm 1 1 m kg 8 0 ft lb T R 28 Nm 2 8 m kg 20 ft lb T R 13 Nm 1 3 m kg 9 4 ft lb ...

Page 111: ...w New E E E Order Job Part Q ty Remarks Removing the cylinder head cylin der and piston Remove the parts in the order listed Center cover side cover left right and footrest board Refer to SIDE COVERS AND FOOT REST BOARD in chapter 3 Muffler gasket Refer to ENGINE REMOVAL 1 Spark plug cap 1 2 Air shroud 2 3 Cylinder head cover 1 4 Spark plug 1 5 Cylinder head 1 6 Cylinder head gasket 1 7 Cylinder 1...

Page 112: ...R 14 Nm 1 4 m kg 10 ft Ib T R 20 Nm 2 0 m kg 14 ft Ib T R 13 Nm 1 3 m kg 9 4 ft Ib T R 28 Nm 2 8 m kg 20 ft Ib New New New New New E E E Order Job Part Q ty Remarks 10 Bearing 1 11 Piston 1 12 Piston ring set 1 13 Cylinder gasket 1 For installation reverse the removal procedure ...

Page 113: ... case 3 1 2 2 Remove piston ring NOTE When removing a piston ring open the end gap with your fingers and lift the other side of the ring over the piston crown EAS00227 CHECKING THE CYLINDER HEAD 1 Eliminate combustion chamber carbon deposits with a rounded scraper NOTE Do not use a sharp instrument to avoid damag ing or scratching spark plug bore threads 2 Check cylinder head Damage scratches Repl...

Page 114: ...CKING 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 bore C with the cylinder bore gauge NOTE Measure cylinder bore C by taking side to side and front to back measurements of the cylinder Then find the average of the mea surements C...

Page 115: ...tion rebore or replace the cylinder and replace the piston and piston rings as a set Piston size P Standard 39 952 39 969 mm 1 5729 1 5736 in Oversize 1 40 25 mm 1 58 in Oversize 2 40 5 mm 1 59 in Piston to cylinder clearance Cylinder bore C Piston skirt diameter P Piston to cylinder clearance 0 036 0 048 mm 0 0014 0 0019 in Limit 0 1 mm 0 0039 in EAS00263 CHECKING THE PISTON RINGS 1 Measure pisto...

Page 116: ...10 mm 0 39 in 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 end gap Top ring 0 15 0 35 mm 0 006 0 014 in Limit 0 70 mm 0 028 in 2nd ring 0 15 0 35 mm 0 006 0 014 in Limit 0 70 mm 0 028 in EAS00265 CHECKING THE PISTON PIN 1 C...

Page 117: ...ecification Replace the piston pin Piston pin bore diameter in the piston 10 004 10 015 mm 0 3939 0 3943 in Limit 10 045 mm 0 3955 in 4 Calculate piston pin to piston pin bore clearance Out of specification Replace the piston pin and piston as a set Piston pin to piston pin bore clearance Piston pin bore diameter Piston pin outside diameter a Piston pin to piston clearance 0 004 0 019 mm 0 00016 0...

Page 118: ... the cylinder align the piston ring end gaps to the respective knock pins as shown 1 2 2 Install bearing piston 1 piston pin 2 piston pin clip 3 NOTE Lubricate the piston pin with engine oil Make sure the arrow mark a on the piston points towards the exhaust side of the cylin der Before installing the piston pin clip cover the crankcase opening with a clean rag to pre vent the clip from falling in...

Page 119: ...nt 5 Install cylinder 2 NOTE While compressing the piston rings with one hand install the cylinder with the other hand cylinder head gasket cylinder head Recommended lubricant Yamalube 2 cycle oil or 2 stroke engine oil T R Cylinder nut 14 Nm 1 4 m kg 10 ft lb 1 2 New New CYLINDER HEAD CYLINDER AND PISTON 5 ...

Page 120: ...r Job Part Q ty Remarks Removing the sheave cover Remove the parts in the order listed Air filter case assembly Refer to CARBURETOR in chapter 6 Transmission oil Drain 1 Kickstarter crank 1 2 Cover 1 3 Damper 1 4 Ground lead 1 5 Sheave cover 1 6 Dowel pin 2 For installation reverse the removal procedure ...

Page 121: ...arks Disassembling the kickstarter shaft Remove the parts in the order listed 1 Kickstarter pinion gear 1 2 Kickstarter pinion gear clip 1 3 Circlip 1 4 Washer 1 5 Kickstarter shaft 1 6 Kickstarter spring 1 7 Spacer 1 For assembly reverse the disassembly procedure 5 ...

Page 122: ...auge Out of specification Replace the kick starter pinion gear clip Kickstarter pinion gear clip force 0 15 0 25 kg 0 34 0 56 lb EAS00340 INSTALLING THE KICKSTARTER 1 Install kickstarter shaft 1 kickstarter spring 2 spacer washer circlip NOTE Install the wire 3 onto the kickstarter spring Install the kickstarter spring straight end on the kickstarter shaft notch 4 and hook the spring hooked end on...

Page 123: ...arks Removing the V belt primary and secondary pulley Remove the parts in the order listed Sheaves cover Refer to KICK STARTER Air shroud fan Refer to GENERATOR AND AUTOL UBE PUMP 1 O ring 1 2 Clutch housing 1 3 Secondary pulley 1 4 V belt 1 5 Conical spring washer 1 6 Kickstarter one way clutch 1 7 Claw washer 1 8 Primary fixed sheave 1 9 Washer 1 10 Spacer 1 5 ...

Page 124: ...0 11 12 15 14 13 T R 30 Nm 3 0 m kg 22 ft Ib T R 40 Nm 4 0 m kg 29 ft Ib Order Job Part Q ty Remarks 11 Collar 1 12 Primary sliding sheave 1 13 Slider 1 14 Cam 1 15 Primary pulley weight 6 16 Gasket 1 For installation reverse the removal procedure ...

Page 125: ... Q ty Remarks Disassembling the secondary pulley Remove the parts in the order listed 1 Clutch carrier nut 1 2 Clutch carrier 1 3 Clutch spring 2 4 Spring 1 5 Spring seat 1 6 Pin 2 7 Secondary sliding sheave 1 8 O ring 2 9 Oil seal 1 0 Secondary fixed sheave 1 For assembly reverse the disassembly procedure 5 ...

Page 126: ...701 3 2 1 3 Remove secondary pulley 1 V belt 2 NOTE Pull the secondary sliding sheave out as shown remove the V belt from the primary pulley and then remove the secondary pulley 1 along with the V belt 2 2 1 4 Loosen clutch carrier nut 1 CAUTION Do not remove the clutch carrier nut at this stage NOTE While holding the clutch carrier with the rotor holding tool 2 loosen the clutch carrier nut one f...

Page 127: ...0319 DISASSEMBLING THE SECONDARY PULLEY 1 Remove clutch carrier nut 1 NOTE Install the clutch spring holder 2 onto the sec ondary pulley as shown Then compress the spring and remove the clutch carrier nut 1 EAS00291 CHECKING THE CLUTCH SHOES The following procedure applies to all of the clutch shoes 1 Check clutch shoe Damage wear Replace the clutch shoes as a set Glazed areas Sand with course san...

Page 128: ...imit 105 5 mm 4 15 in EAS00322 CHECKING THE SECONDARY PULLEY 1 Check secondary fixed sheave secondary sliding sheave Cracks damage wear Replace the sec ondary fixed and sliding sheaves as a set 2 Check guide pin groove 1 Damage wear Replace the secondary fixed and sliding sheaves as a set 3 Check guide pin 2 Damage wear Replace the secondary fixed and sliding sheaves as a set 2 1 4 Check spring fr...

Page 129: ... Replace V belt width 16 6 mm 0 65 in Limit 15 0 mm 0 59 in 1 EAS00321 CHECKING THE PRIMARY PULLEY WEIGHTS The following procedure applies to all of the primary pulley weights 1 Check primary pulley weight Cracks damage wear Replace 2 Measure primary pulley weight outside diameter a Out of specification Replace Primary pulley weight outside diameter 15 0 mm 0 59 in Limit 14 5 mm 0 57 in 5 ...

Page 130: ... lubricant 2 Install secondary sliding sheave 1 NOTE Install the secondary sliding sheave onto the secondary fixed sheave 2 with the oil seal guide 3 Recommended lubricant Lithium soap base grease Oil seal guide YM 01409 LS LS 1 2 2 1 3 3 Install guide pin 1 1 4 Lubricate guide pin groove 2 O ring 3 with the recommended lubricant Recommended lubricant Lithium soap base grease 2 LS 3 New ...

Page 131: ... pulley as shown Then compress the spring and tighten the clutch carrier nut 5 Clutch spring holder YS 28891 4 3 5 1 2 EAS00323 INSTALLING THE PRIMARY PULLEY 1 Clean primary fixed sheave primary sliding sheave spacer primary pulley weights 2 Install primary pulley weights 1 slider 2 cams 3 1 1 3 1 3 3 2 3 Install primary sliding sheave 4 collar 5 spacer 6 5 4 6 5 ...

Page 132: ...ion While holding the generator rotor with the rotor holding tool tighten the primary sheave nut Rotor holding tool YU 01235 B A 0 9 8 7 0 A T R 30 Nm 3 0 m kg 22 ft lb EAS00325 INSTALLING THE BELT DRIVE 1 Install clutch carrier nut 1 NOTE While holding the clutch carrier with the rotor holding tool 2 tighten the clutch carrier nut with the locknut wrench Rotor holding tool YU 01235 1 2 T R 50 Nm ...

Page 133: ...ary pulley 2 along with the V belt 1 3 2 1 3 Install clutch housing 1 clutch housing nut 2 NOTE Tighten the clutch housing nut while holding the clutch housing with the sheave holder 3 Sheave holder YU 01701 2 3 1 T R 40 Nm 4 0 m kg 29 ft lb 4 Position V belt 1 NOTE Position the V belt on the primary pulley 2 when the pulley is at its widest position and on the secondary pulley 3 when the pulley i...

Page 134: ...marks Removing the starter clutch and starter motor Remove the parts in the order listed Sheaves cover Refer to KICKSTARTER Primary sliding sheave Refer to BELT DRIVE 1 Idle gear plate 1 2 Washer 2 3 Idle gear 1 4 Starter clutch assembly 1 5 Starter wheel gear 1 6 Bearing 1 7 Spacer 1 8 Starter motor coupler 1 Disconnect 9 Starter motor 1 For installation reverse the removal procedure ...

Page 135: ... 1 4 Check starter clutch operation a Install the starter wheel gear onto the starter clutch and hold the starter clutch b When turning the starter wheel gear clock wise È the starter clutch and the starter wheel gear should engage otherwise the starter clutch is faulty and must be replaced c When turning the starter wheel gear coun terclockwise É it should turn freely other wise the starter clutc...

Page 136: ...5 29 ENG STARTER CLUTCH AND STARTER MOTOR 2 Install starter wheel gear 1 starter clutch assembly 2 NOTE Install the starter clutch assembly 1 while turning the starter wheel gear 2 clockwise 2 1 ...

Page 137: ...Ib 10 Order Job Part Q ty Remarks Removing the transmission Remove the parts in the order listed Transmission oil Drain Rear wheel Refer to REAR WHEEL AND BRAKE in chapter 4 Secondary pulley Refer to BELT DRIVE 1 Transmission cover 1 2 Gasket 1 3 Dowel pin 2 4 Washer 1 5 Conical spring washer 1 6 Main axle 1 7 Drive axle 1 8 Secondary drive gear 1 5 ...

Page 138: ...8 6 5 4 7 11 1 2 3 3 9 New New New G G LS LT LT New T R 9 Nm 0 9 m kg 6 5 ft Ib T R 18 Nm 1 8 m kg 13 ft Ib 10 Order Job Part Q ty Remarks 9 Circlip 1 10 Bearing 1 11 Oil seal 1 For installation reverse the removal procedure ...

Page 139: ...NSMISSION 1 Check drive axle main axle secondary drive gear Damage wear Replace 2 Check bearing Rough movement Replace 3 Check secondary drive gear movement Rough movement Replace the defective part 4 Check circlips Bends damage looseness Replace 5 ...

Page 140: ...g the stator coil assembly Remove the parts in the order listed Center cover side cover right and footrest board Refer to SIDE COVERS AND FOOT REST BOARD in chapter 3 1 Coupler cover 1 2 Air shroud 1 3 Fan 1 4 Generator rotor 1 5 Stator coil assembly coupler 1 Disconnect 6 Stator coil assembly 1 7 Woodruff key 1 8 Gasket 1 For installation reverse the removal procedure ...

Page 141: ...Q ty Remarks Removing the autolube pump Remove the parts in the order listed Stator coil assembly Refer to GENERATOR AND AUTOL UBE PUMP 1 Spark plug cap 1 2 Cylinder head cover 1 3 Circlip 2 4 Pump drive gear 1 5 Pin 1 6 Oil hose 1 7 Oil delivery hose 1 8 Autolube pump 1 9 O ring 1 For installation reverse the removal procedure 5 ...

Page 142: ...move generator rotor 1 with the flywheel puller set 2 woodruff key Flywheel puller set YU 90105 1 2 CHECKING THE AUTOLUBE PUMP 1 Check oil hose 1 Obstruction Blow out with compressed air 2 Check autolube pump 2 pump drive gear 3 Damage Replace INSTALLING THE AUTOLUBE PUMP 1 Install autolube pump 1 pump drive gear 2 CAUTION Push the autolube pump in until it contacts the right crankcase a and then ...

Page 143: ...tor make sure the woodruff key is properly seated in the keyway of the crankshaft Do not allow the rotor holding tool to touch the projection on the generator rotor LS 1 New 2 2 Tighten generator rotor nut 1 NOTE While holding the generator rotor 2 with the rotor holding tool 3 tighten the generator rotor nut 1 Do not allow the rotor holding tool to touch the projection on the generator rotor Roto...

Page 144: ...HEEL AND BRAKE in chapter 4 Engine assembly Refer to ENGINE REMOVAL Cylinder head cylinder and piston Refer to CYLINDER HEAD CYLINDER AND PISTON Sheaves cover Refer to KICKSTARTER V belt and secondary pulley Refer to BELT DRIVE Starter clutch assembly and starter motor Refer to STARTER CLUCH AND STARTER MOTOR Generator rotor Refer to GENERATOR AND AUTOL UBE PUMP Autolube pump Refer to AUTOLUBE PUM...

Page 145: ...3 2 1 6 5 6 New New New Order Job Part Q ty Remarks 1 Cover 1 2 Intake manifold 1 3 Reed valve assembly 1 4 Valve seat gasket 1 5 Bearing retainer 1 6 Right crankcase 1 Refer to DISASSEMBLING THE CRANKCASE 7 Dowel pin 2 8 Engine mount spacer 1 9 Circlip 1 10 Bearing 1 11 Oil seal 1 For installation reverse the removal procedure 5 ...

Page 146: ...mer Tap only on reinforced portions of the crankcase not on the crankcase mating surfaces Work slowly and carefully and make sure the crankcase halves separate evenly NOTE Remove the crankcase separating tool 2 Crankcase separating tool YU 01135 2 1 EAS00399 CHECKING THE CRANKCASE 1 Thoroughly wash the crankcase halves in a mild solvent 2 Thoroughly clean all the gasket surfaces and crankcase mati...

Page 147: ... with your finger Rough movement Replace 2 Check oil seals Damage wear Replace CHECKING THE REED VALVE 1 Measure reed valve bending a Out of specification Replace 2 Measure valve stopper height b Out of specification Adjust stopper replace valve stopper Reed valve bending Limit 0 2 mm 0 008 in Valve stopper height 7 0 7 4 mm 0 28 0 29 in 5 ...

Page 148: ... crankcase Use the crankshaft installing tool 4 Install crankcase screws NOTE Tighten each bolt 1 4 of a turn at a time in stages and in a crisscross pattern 5 Apply engine oil onto the crankshaft pins bearings and oil delivery holes 6 Check crankshaft and transmission operation Rough movement Repair Crankshaft installer pot 2 YU 90058 Crankshaft installer bolt 3 YU 90060 Crankshaft installer adap...

Page 149: ... Order Job Part Q ty Remarks Removing the crankshaft Remove the parts in the order listed Engine assembly Refer to ENGINE REMOVAL Crankcase Separate Refer to CRANKCASE 1 Crankshaft 1 2 Bearing 2 3 Oil seal 1 4 Crankcase 1 1 For installation reverse the removal procedure 5 ...

Page 150: ...KING THE CRANKSHAFT 1 Measure crankshaft runout 1 Out of specification Replace the crank shaft bearing s or both NOTE Turn the crankshaft slowly 2 Measure big end side clearance 2 Out of specification Replace the big end bearing crankshaft pin or connecting rod 3 Measure crankshaft width 3 Out of specification Replace the crank shaft Maximum crankshaft runout 0 03 mm 0 0012 in Big end side clearan...

Page 151: ...tallation procedure lubricate the oil seal lips with grease and each bear ing with engine oil NOTE Hold the connecting rod at top dead center TDC with one hand while turning the nut of the crankshaft installing tool with the other Turn the crankshaft installing tool until the crankshaft assembly bottoms against the bear ing Crankshaft installer pot 1 YU 90058 Crankshaft installer bolt 2 YU 90060 C...

Page 152: ...over left and foot rest board Refer to SIDE COVERS AND FOOT REST BOARD in chapter 3 1 Air filter case assembly 1 2 Clip 1 3 Auto choke coupler 1 Disconnect 4 Oil delivery hose 1 5 Clamp screw intake manifold 1 Loosen 6 Carburetor assembly 1 7 Fuel hose 1 8 Vacuum hose 1 9 Throttle assembly 1 10 O ring 1 For installation reverse the removal procedure CARBURETOR ...

Page 153: ...in the order listed NOTE Before disassembling the carburetor make sure to note the number of times the pilot air screw is turned out from the seated position to its set position 1 Throttle cables 2 2 Throttle valve 1 3 Jet needle kit 1 4 Mixing chamber cap 1 5 Throttle stop screw 1 6 Auto choke assembly 1 7 Float chamber 1 6 ...

Page 154: ... 4 5 3 2 E D C B A 0 9 6 8 7 Order Job Part Q ty Remarks 8 O ring 1 9 Float pivot pin 1 0 Float 1 A Needle valve 1 B Main jet 1 C Needle jet 1 D Pilot jet 1 E Carburetor body 1 For assembly reverse the disassembly procedure ...

Page 155: ...ber jet housing Cracks damage Replace 2 Check fuel passages Obstruction 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 3 Check float chamber body Dirt Clean 4 Check float chamber rubber gasket Cracks damage wear Replace 5 Check float Damage Replace 6 Check needle valve 1 Damage...

Page 156: ...wn Tightness Replace the piston valve 10 Check vacuum hose fuel hose Cracks damage wear Replace Obstruction Clean Blow out the hoses with compressed air EAS00487 ASSEMBLING THE CARBURETOR NOTE Before assembling the carburetor make sure to turn out the pilot air screw the same number of times as noted before disassembly from the seated position to the set position CAUTION Before assembling the carb...

Page 157: ...e of the throttle valve with the projection of the carburetor body 6 Install throttle cable EAS00492 INSTALLING THE CARBURETOR 1 Adjust engine idling speed Refer to ADJUSTING THE ENGINE IDLING SPEED in chapter 3 2 Adjust throttle cable free play Refer to ADJUSTING THE THROTTLE CABLE FREE PLAY in chapter 3 Engine idling speed 1 800 r min Throttle cable free play at the flange of the throttle grip 1...

Page 158: ...ight is not within specification check the needle valve e If either is worn replace them as a set f Install the carburetor Float height 15 17 mm 0 59 0 67 in EAS00503 CHECKING THE AUTOCHOKE ASSEMBLY NOTE When checking the autochoke assembly the ambient temperature must be lower than 45 C 113 F 1 Remove carburetor 2 Check autochoke assembly a Connect a 3 3 mm hose 1 to the starter air passage 2 and...

Page 159: ...blow into the hose Positive battery lead 1 black Negative battery lead 2 black Starter plunger opens Replace the auto choke assembly Starter plunger closes Autochoke is OK 4 3 1 2 B B EAS00506 CHECKING THE FUEL COCK OPERATION NOTE After installing the fuel cock check its opera tion 1 Place a container under the end of the fuel hose 1 1 2 Check fuel cock operation a Suck on the end of the vacuum ho...

Page 160: ...NENTS 1 Main switch 2 Starter relay 3 Fuel sender 4 Oil level switch 5 CDI unit 6 Rectifier regulator 7 Main fuse 8 Battery 9 Spark plug cap 0 Ignition coil A Wire harness B Turn signal relay C Horn 1 C B A 0 9 8 7 6 5 4 3 2 ELECTRICAL COMPONENTS ...

Page 161: ...to the Ω 1 range When checking for continuity 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 cont...

Page 162: ...CHES Check each switch for damage or wear proper connections and also for continuity between the ter minals Refer to CHECKING SWITCH CONTINUITY Damage wear Repair or replace Improperly connected Properly connect Incorrect continuity reading Replace the switch ...

Page 163: ...7 4 ELEC CHECKING THE SWITCHES 1 Front brake light switch 2 Turn signal switch 3 Dimmer switch 4 Horn switch 5 Main switch 6 Rear brake light switch 7 Start switch 8 Engine stop switch 9 Main fuse 7 ...

Page 164: ...S The bulbs used on this scooter are shown in the 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 are used for turn signal and tail brake lights and can be removed from the socket by...

Page 165: ...ther wise the transparency of the glass the life of the bulb 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 t...

Page 166: ...ster No continuity 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 YU 0311...

Page 167: ...Y R BLACK RED RED BLACK BLACK B O L W Br B W L L Y E Br G Y Br G Y B B GREEN GREEN F H I G Br Br L G Y Gy B Gy B Gy G Y Br G Y B B Y G G Y GREEN GREEN Z Br B G B B B Gy Br W Br Y G B G Y T S X U V W Br B Br W Gy Y Br W Gy Br Y B L Y B G Y B L J Br W Br Gy B Gy Br W Br Br W O N Ch Dg L P P Br Br W Dg L P Ch B L Ch Br W B Dg P RED RED Q R Ch G Y G B Y B B Q Dg B P Ch B P Dg B B G Y M L N K A R B R B...

Page 168: ...park tester YU 34487 Pocket tester YU 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 main fuse 2 Battery Check the condition of the battery Refer to CHECKING AND CHARGING THE BATTERY in chapter 3 Minimum open circuit voltage 12 8 V or more at 20 C 68 F Is the battery OK Clean the battery terminals Recharge or replace th...

Page 169: ...itch 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 5 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 Spark plug cap resistance...

Page 170: ... 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 2 1 1 2 7 Pickup coil resistance Disconnect the stator coil assembly cou pler from the wire harness Connect the pocket tester Ω 100 to the pickup coil terminal as shown Positive tester probe white red 1 Negative tester probe white blue 2 Measure the pickup co...

Page 171: ...G THE SWITCHES Is the engine stop switch OK Replace the right handlebar switch 10 Wiring Check the entire ignition system s wiring Refer to CIRCUIT DIAGRAM Is the ignition system s wiring properly connected and without defects Replace the ignitor unit Properly connect or repair the ignition system s wiring IGNITION SYSTEM 7 ...

Page 172: ...BLACK BLACK B O L W Br B W L L Y E Br G Y Br G Y B B GREEN GREEN F H I G Br Br L G Y Gy B Gy B Gy G Y Br G Y B B Y G G Y GREEN GREEN Z Br B G B B B Gy Br W Br Y G B G Y T S X U V W Br B Br W Gy Y Br W Gy Br Y B L Y B G Y B L J Br W Br Gy B Gy Br W Br Br W O N Ch Dg L P P Br Br W Dg L P Ch B L Ch Br W B Dg P RED RED Q R Ch G Y G B Y B B Q Dg B P Ch B P Dg B B G Y M L N K A R B R B MAIN HARNESS WIRE...

Page 173: ... the main fuse for continuity Refer to CHECKING THE FUSE in chap ter 3 Is the main fuse OK Replace the main fuse 2 Battery Check the condition of the battery Refer to CHECKING AND CHARGING THE BATTERY in chapter 3 Minimum open circuit voltage 12 8 V or more at 20 C 68 F Is the battery OK Clean the battery terminals Recharge or replace the battery 3 Starter motor Connect the positive battery termin...

Page 174: ...er relay 5 Main switch Check the main switch for continuity Refer to CHECKING THE SWITCHES Is the main switch OK Replace the main switch 6 Engine stop switch Check the engine stop switch for continu ity Refer to CHECKING THE SWITCHES Is the engine stop switch OK Replace the right handlebar switch 7 Start switch Check the start switch for continuity Refer to CHECKING THE SWITCHES Is the start switc...

Page 175: ...Is the rear brake light switch OK Replace the rear brake light switch 10 Wiring Check the entire starting system s wiring Refer to CIRCUIT DIAGRAM Is the starting system s wiring properly connected and without defects The starting system circuit is OK Properly connect or repair the starting system s wiring ELECTRIC STARTING SYSTEM 7 ...

Page 176: ... Job Part Q ty Remarks Removing the starter motor Remove the parts in the order listed Air shroud Refer to CYLINDER HEAD CYLINDER AND PISTON in chapter 5 1 Starter motor coupler 1 2 Starter motor assembly 1 For installation reverse the removal procedure ...

Page 177: ... Q ty Remarks Disassembling the starter motor Remove the parts in the order listed 1 O ring 1 2 Starter motor yoke 1 3 Armature assembly 1 4 Gasket 2 5 Brush holder 1 6 Starter motor cover 1 For assembly reverse the disassembly procedure STARTER MOTOR 7 ...

Page 178: ...ndercut a Out of specification Scrape the mica to the proper measurement with a hacksaw blade that has been grounded to fit the commutator NOTE The mica must be undercut to ensure proper operation of the commutator 4 Measure armature assembly resistances commuta tor and insulation Out of specification Replace the starter motor a Measure the armature assembly resis tances with the pocket tester Mic...

Page 179: ...t of specification Replace the brushes as a set 6 Measure brush spring force Out of specification Replace the brush springs as a set 7 Check gear teeth Damage wear Replace the gear Brush length wear limit 0 9 mm 0 04 in Brush spring force 2 32 3 48 N 236 5 355 0 gf 8 35 12 53 oz EAS00772 ASSEMBLING THE STARTER MOTOR 1 Install starter motor yoke 1 starter motor cover 2 3 Install O ring 1 screws 2 N...

Page 180: ... L W B L Y L W L W B L W B L W B W L B W Y R W W L W R Y R A A BLACK 0 B A B B B Y R BLACK BLACK BLACK B O L W Br B W L L Y H I Br Gy B Gy B Gy Y G G Y G B B Gy Br W Br Y G Y T S U V W Br B Br W Gy Y Br W Gy Br Y B J Br W Br Gy B Gy Br W Br Br W O N Ch Dg L P P Br Br W Dg L P Ch B L Ch Br W B Dg P RED RED Q R Ch G Y G B Y B B Q Dg B P Ch B P Dg B B G Y M L N K 2 Battery 3 Main fuse 4 Rectifier reg...

Page 181: ...SE in chap ter 3 Is the main fuse OK Replace the main fuse 2 Battery Check the condition of the battery Refer to CHECKING AND CHARGING THE BATTERY in chapter 3 Minimum open circuit voltage 12 8 V or more at 20 C 68 F Is the battery OK Clean the battery terminals Recharge or replace the battery 3 Charging voltage Connect the inductive tachometer to the spark plug lead Connect the pocket tester DC 2...

Page 182: ...specifica tion The charging circuit is OK 4 Wiring Check the wiring connections of the entire charging system Refer to CIRCUIT DIAGRAM Is the charging system s wiring properly connected and without defects Replace the recti fier regulator Properly connect or repair the charging system s wiring CHARGING SYSTEM ...

Page 183: ...BLACK B O L W Br B W L L Y E Br G Y Br G Y B B GREEN GREEN F H I G Br Br L G Y Gy B Gy B Gy G Y Br G Y B B Y G G Y GREEN GREEN Z Br B G B B B Gy Br W Br Y G B G Y T S X U V W Br B Br W Gy Y Br W Gy Br Y B L Y B G Y B L J Br W Br Gy B Gy Br W Br Br W O N Ch Dg L P P Br Br W Dg L P Ch B L Ch Br W B Dg P RED RED Q R Ch G Y G B Y B B Q Dg B P Ch B P Dg B B G Y M L N K A R B R B MAIN HARNESS WIRE LEAD ...

Page 184: ...ht Pocket tester YU 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 main fuse 2 Battery Check the condition of the battery Refer to CHECKING AND CHARGING THE BATTERY in chapter 3 Minimum open circuit voltage 12 8 V or more at 20 C 68 F Is the battery OK Clean the battery terminals Recharge or replace the battery 3 Main s...

Page 185: ... head light bulb socket or both 2 Voltage Connect the pocket tester DC 20 V to the headlight and high beam indicator light couplers as shown È When the dimmer switch is set to É When the dimmer switch is set to Headlight coupler wire harness side Positive tester probe yellow 1 Negative tester probe black 3 Headlight Positive tester probe yellow 1 or green 2 Negative tester probe black 3 High beam ...

Page 186: ...eter light bulb and socket Check the meter light bulb and socket for continuity Are the meter light bulb and socket OK Replace the meter light bulb socket or both W R W L Y R W 1 3 2 2 Voltage Connect the pocket tester 20 V to the meter light coupler wire harness side as shown Positive tester probe brown 1 Negative tester probe black 2 Meter light assembly coupler Set the main switch to ON Measure...

Page 187: ...lue 1 Negative tester probe black 2 Set the main switch to ON Measure the voltage 12 V of blue 1 on the tail brake light coupler tail brake light side Is the voltage within specification This circuit is OK The wiring circuit from the main switch to the tail brake light coupler is faulty and must be repaired L Y B G Y B L 1 2 LIGHTING SYSTEM 7 ...

Page 188: ... Y R W W L W R Y R A A BLACK 0 B A B B B Y R BLACK RED RED BLACK BLACK B O L W Br B W L L Y E Br G Y Br G Y B B GREEN GREEN F H I G Br Br L G Y Gy B Gy B Gy G Y Br G Y B B Y G G Y GREEN GREEN Z Br B G B B B Gy Br W Br Y G B G Y T S X U V W Br B Br W Gy Y Br W Gy Br Y B L Y B G Y B L J Br W Br Gy B Gy Br W Br Br W O N Ch Dg L P P Br Br W Dg L P Ch B L Ch Br W B Dg P RED RED Q R Ch G Y G B Y B B Q D...

Page 189: ...brake light H Oil level gauge I Diode J Turn signal relay K Horn M Horn switch O Turn signal switch P Rear turn signal light Q Front turn signal light T Oil level warning light W Turn signal indicator light X Fuel gauge assembly Y Fuel level gauge Z Fuel level indicator light Fuel sender SIGNALING SYSTEM 7 ...

Page 190: ...to CHECKING THE FUSE in chap ter 3 Is the main fuse OK Replace the main fuse 2 Battery Check the condition of the battery Refer to CHECKING AND CHARGING THE BATTERY in chapter 3 Minimum open circuit voltage 12 8 V or more at 20 C 68 F Is the battery OK Clean the battery terminals Recharge or replace the bat tery 3 Main switch Check the main switch for continuity Refer to CHECKING THE SWITCHES Is t...

Page 191: ...hown Positive tester probe brown 1 Negative tester probe ground Set the main switch to ON Push the horn switch Measure the voltage 12 V of brown at the horn terminal Is the voltage within specification The wiring circuit from the main switch to the horn connec tor is faulty and must be repaired 3 Horn Disconnect the pink connector at the horn terminal Connect a jumper lead 1 to the horn ter minal ...

Page 192: ...d socket OK Replace the tail brake light bulb socket or both 2 Brake light switches Check the brake light switches for continu ity Refer to CHECKING THE SWITCHES Is the brake light switch OK Replace the brake light switch 3 Voltage Connect the pocket tester DC 20 V to the tail brake light coupler wire harness side as shown Positive tester probe green yellow 1 Negative tester probe black 2 Set the ...

Page 193: ...he turn signal switch for continuity Refer to CHECKING THE SWITCHES Is the turn signal switch OK Replace the left han dlebar switch 3 Voltage Connect the pocket tester DC 20 V to the turn signal relay coupler wire harness side as shown Positive tester probe brown 1 Negative tester probe ground Set the main switch to ON Measure the voltage 12 V on brown 1 at the turn signal relay coupler wire harne...

Page 194: ...ector wire harness side as shown È Turn signal light Left turn signal light Positive tester probe chocolate 1 Negative tester probe ground Right turn signal light Positive tester probe dark green 2 Negative tester probe ground É Turn signal indicator light Positive tester probe brown 3 Negative tester probe brown white 4 Set the main switch to ON Set the turn signal switch to or Measure the voltag...

Page 195: ...terminal 2 Check the oil level switch for continuity Hold the oil level switch in an upright posi tion È and let the float 3 go all the way down É Is the oil level switch OK Replace the oil level switch 1 2 3 3 Diode Remove the diode from the wire harness Connect the pocket tester Ω 1 to the diode terminals as shown Check the diode for continuity as follows Tester positive probe gray 1 Tester nega...

Page 196: ... is faulty and must be repaired 1 Fuel level indicator light bulb and socket Check the fuel level indicator light bulb and socket for continuity Are the fuel level indicator light bulb and socket OK Replace the fuel level indicator light bulb socket or both Br B Br W Gy Y Br W Gy Br Y B 1 2 2 Fuel sender Remove the fuel sender from the fuel tank Connect the pocket tester to the fuel sender coupler...

Page 197: ...e fuel level gauge 1 2 4 Voltage Connect the pocket tester DC 20 V to the fuel level gauge coupler wire harness side as shown Fuel level gauge Positive tester probe brown 1 Negative tester probe green 2 Fuel level indicator light Positive tester probe brown 1 Negative tester probe black 3 Set the main switch to ON Measure the voltage 12 V of brown 1 on the fuel level gauge coupler wire harness sid...

Page 198: ...STEM AUTO CHOKE SYSTEM CIRCUIT DIAGRAM O O B B Br B L W L Y W Y R Y R W L W L R W L B W Y R W W L W R Y R LACK 0 B A B B B Y R BLACK BLACK BLACK B O L W Br B W L L Y F Br Br Gy B B J Br Gy B Gy Br W 0 AC magneto A Auto choke ...

Page 199: ...rness Connect the pocket tester Ω 1 to the auto choke coupler as shown Tester positive probe black 1 Tester negative probe black 2 Auto choke resistance 8 12 Ω at 20 C 68 F Is the auto choke unit OK Replace the auto choke B B 2 1 2 Source coil resistance Disconnect the stator coil assembly cou pler from wire harness Connect the pocket tester Ω 1 to the source coil lead Tester positive probe yellow...

Page 200: ...yellow red 1 Tester negative probe black 2 Set the main switch to ON Start the engine and accelerate to about 3 000 r min Check the voltage Voltage 12 8 V or more at 20 C 68 F This auto choke is OK Check the entire auto choke unit for connection Refer to the CIR CUIT DIAGRAM B B B Y R 2 1 AUTO CHOKE SYSTEM ...

Page 201: ...minated fuel Clogged pilot jet Clogged pilot air passage Sucked in air Damaged float Worn needle valve Improperly installed needle valve seat Incorrect fuel level Improperly adjusted pilot air screw Improperly installed pilot jet Clogged starter jet Clogged emulsion tube Autochoke unit Faulty starter plunger Faulty ignitor unit ELECTRICAL SYSTEMS Battery Improperly charged battery Faulty battery F...

Page 202: ...filter Clogged air filter element FUEL SYSTEM Carburetor Faulty diaphragm Incorrect fuel level Loose or clogged main jet EAS00853 FAULTY CLUTCH ENGINE OPERATES BUT SCOOTER WILL NOT MOVE V belt Bent damaged or worn V belt Slipping V belt Primary pulley cam and primary pulley slider Damaged or worn primary pulley cam Damaged or worn primary pulley slider Transmission gear s Damaged transmission gear...

Page 203: ...ct brake camshaft lever position Incorrect brake shoe position Damaged or fatigued brake shoe spring Oil or grease on the brake shoe Oil or grease on the brake drum Broken brake torque rod EAS00862 UNSTABLE HANDLING Handlebar Bent or improperly installed handlebar Steering head components Improperly installed lower handlebar holder Improperly installed fork improperly tightened ring nut Bent steer...

Page 204: ...LIGHT BULB BURNT OUT Wrong tail brake light bulb Faulty battery Tail brake light bulb life expired TURN SIGNAL DOES NOT LIGHT Faulty turn signal switch Faulty turn signal relay Burnt out turn signal bulb Incorrect connection Damaged or faulty wire harness Improperly grounded circuit Faulty battery Blown damaged or incorrect fuse TURN SIGNAL BLINKS SLOWLY Faulty turn signal relay Faulty main switch...

Page 205: ...YAMAHA MOTOR CO LTD 2500 SHINGAI IWATA SHIZUOKA JAPAN PRINTED IN U S A ...

Page 206: ...r Gy R Gy Br R R W 1 2 3 O O B C D B R R R B B B B B Br B L W L Y Y R W Y R Y R W L W L R R R R G Y R L W 4 Y R W B R R L W R G Y R R R B R 5 6 7 8 9 L Y L W L W B L Y L W L W B L W B L W B Br G B G Br B W L B W Y R W W L W R Y R A A BLACK 0 B A B B B Y R BLACK RED RED BLACK BLACK B O L W Br B W L L Y E Br G Y Br G Y B B GREEN GREEN F H I G Br Br L G Y Gy B Gy B Gy G Y Br G Y B B Y G G Y B G GREEN...

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Yamaha Vino YJ50RN, Service Manual

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