YAMAHA YJ125S service manual

YJ125S

SERVICE MANUAL

LIT-11616-17-43 5YR-28197-10

EAS00000

YJ125S 2003

SERVICE MANUAL

First edition, November 2003

Any reproduction or unauthorized use

without the written permission of

Yamaha Motor Taiwan Co., Ltd.

is expressly prohibited.

Printed in U.S.A.

LIT-11616-17-43

EAS00002

NOTICE

This manual was produced by the Yamaha Motor Taiwan Company, Ltd. primarily for use by Yamaha dealers and their qualified mechanics. It is not possible to include all the knowledge of a mechanic in one manual. Therefore, anyone who uses this book to perform maintenance and repairs on Yamaha vehicles should have a basic understanding of mechanics and the techniques to repair these types of vehicles. Repair and maintenance work attempted by anyone without this knowledge is likely to render the vehicle unsafe and unfit for use.

Yamaha Motor Taiwan Company, Ltd. is continually striving to improve all of its models. Modifications and significant changes in specifications or procedures will be forwarded to all authorized Yamaha dealers and will appear in future editions of this manual where applicable.

NOTE:

Designs and specifications are subject to change without notice.

EAS00005

IMPORTANT MANUAL INFORMATION

Particularly important information is distinguished in this manual by the following.

The Safety Alert Symbol means ATTENTION! BECOME ALERT! YOUR SAFETY IS INVOLVED!

NOTE:

The Safety Alert Symbol means ATTENTION] BECOME ALERT! YOUR SAFETY IS INVOLVED!

Failure to follow WARNING instructions could result in severe injury or death to the scooter operator, a bystander or a person inspecting or repairing the scooter.

A CAUTION indicates special precautions that must be taken to avoid damage to the scooter.

A NOTE provides key information to make procedures easier or clearer.

HOW TO USE THIS MANUAL

This manual is intended as a handy, easy-to-read reference book for the mechanic. Comprehensive explanations of all installation, removal, disassembly, assembly, repair and check procedures are laid out with the individual steps in sequential order.

1 The manual is divided into chapters. An abbreviation and symbol in the upper right corner of

each page indicate the current chapter. Refer to “SYMBOLS”.

2 Each chapter is divided into sections. The current section title is shown at the top 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

a disassembly step.

6 Symbols indicate parts to be lubricated or replaced.

Refer to “SYMBOLS”.

7 A job instruction chart accompanies the exploded diagram, providing the order of jobs, names

of parts, notes in jobs, etc.

8 Jobs requiring more information (such as special tools and technical data) are described se-

quentially.

EAS00251

CYLINDER AND PISTON

12Nm(1.2m • kg, 8.7 ft • lb)

Removing the cylinder and piston

Cylinder head Clamp

Pipe

Timing chain guide (exhaust side)

Cylinder

O-ring

Dowel pin

Cylinder gasket

Piston pin clip

Piston pin

Piston

Top ring

2nd ring

Oil ring

Expander

CYLINDER AND PISTON

Remove the parts in the order listed.

Refer to “CYLINDER HEAD”. 1 1 1 1 1 2

Refer to “ INSTALLING THE PISTON

AND CYLINDER” 2

Refer to “ REMOVING THE CYLINDER

AND PISTON” 1

Refer to “ INSTALLING THE PISTON

AND CYLINDER” 1 2 1

For installation, reverse the removal pro-

cedure.

5-28

ENG

RemarksOrder Job/Part Q’ty

CYLINDER AND PISTON

EAS00253

REMOVING THE CYLINDER AND PISTON

1. Remove:

8piston pin clip 1 8piston pin 2 8piston 3

Do not use a hammer to drive the piston pin out.

NOTE:

8 Before removing the piston pin clip, cover

the crankcase opening with a clean rag to prevent the piston pin clip from falling into the crankcase.

8 Before removing the piston pin, deburr the

piston pin clip’s groove and the piston’s pin bore area.

2. Remove:

8top ring 82nd ring 8oil 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.

5-29

ENG

GEN

SPEC

INFO

EAS00008

SYMBOLS

The following symbols are not relevant to every vehicle. Symbols 1 to 9 indicate the subject of each chapter.

CHK

ADJ

ENG

CARB

CHAS

COOL

ELEC

TRBL

SHTG

1 General information 2 Specifications 3 Periodic checks and adjustments 4 Chassis 5 Engine 6 Cooling system 7 Carburetor(s) 8 Electrical system 9 Troubleshooting

Symbols 0 to u indicate the following.

0 Serviceable with engine mounted q Filling fluid w Lubricant e Special tool r Tightening torque t Wear limit, clearance y Engine speed u Electrical data

t y u

iop

asd

New

Symbols i to d in the exploded diagrams indicate the types of lubricants and lubrication points.

i Engine oil o Gear oil p Molybdenum-disulfide oil a Wheel-bearing grease s Lithium-soap- based grease d Molybdenum-disulfide grease

Symbols f to g in the exploded diagrams indicate the following.

f Apply locking agent (LOCTITE g Replace the part

)

EAS00011

GENERAL INFORMATION

SPECIFICATIONS

PERIODIC CHECKS AND ADJUSTMENTS

CHASSIS

ENGINE

GEN

INFO

SPEC

CHK

ADJ

CHAS

ENG

CARBURETOR

ELECTRICAL SYSTEM

TROUBLESHOOTING

CARB

ELEC

TRBL SHTG

GEN

INFO

CHAPTER 1

GENERAL INFORMATION

SCOOTER IDENTIFICATION ................................................................... 1-1

VEHICLE IDENTIFICATION NUMBER ............................................. 1-1

MODEL LABEL .................................................................................. 1-1

IMPORTANT INFORMATION................................................................... 1-2

PREPARATION FOR REMOVAL AND DISASSEMBLY ................... 1-2

REPLACEMENT PARTS ................................................................... 1-2

GASKETS, OIL SEALS AND O-RINGS ............................................ 1-2

LOCK WASHERS/PLATES AND COTTER PINS............................. 1-3

BEARINGS AND OIL SEALS ............................................................ 1-3

CIRCLIPS ........................................................................................... 1-3

CHECKING THE CONNECTIONS ........................................................... 1-4

SPECIAL TOOLS...................................................................................... 1-5

1-8

SCOOTER IDENTIFICATION

EAS00015

GENERAL INFORMATION

SCOOTER IDENTIFICATION

EAS00017

VEHICLE IDENTIFICATION NUMBER

The vehicle identification number 1 is stamped into the steering head pipe.

EAS00018

MODEL LABEL

The model label 1 is affixed to the seat. This information will be needed to order spare parts.

GEN

INFO

1-1

IMPORTANT INFORMATION

EAS00020

IMPORTANT INFORMATION

PREPARATION FOR REMOVAL AND DISASSEMBLY

1. Before removal and disassembly, remove all dirt, mud, dust and foreign material.

2. Use only the proper tools and cleaning equipment.

Refer to the “SPECIAL TOOLS”.

3. When disassembling, always keep mated parts together. This includes gears, cylinders, pistons and other parts that have been “mated” through normal wear. Mated parts must always be reused or replaced as an assembly.

4. During disassembly, clean all of the parts and place them in trays in the order of disassembly. This will speed up assembly and allow for the correct installation of all parts.

5. Keep all parts away from any source of fire.

GEN

INFO

EAS00021

REPLACEMENT PARTS

Use only genuine Yamaha parts for all replacements. Use oil and grease recommended 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, seals and O-rings. All gasket surfaces, oil seal lips and O-rings must be cleaned.

2. During reassembly, properly oil all mating parts and bearings and lubricate the oil seal lips with grease.

1-2

IMPORTANT INFORMATION

EAS00023

LOCK WASHERS/PLATES AND COTTER PINS

After removal, replace all lock washers/plates 1 and cotter pins. After the bolt or nut has been tightened to specification, bend the lock tabs along a flat of the bolt or nut.

EAS00024

BEARINGS AND OIL SEALS

Install bearings and oil seals so that the manufacturer’s marks or numbers are visible. When installing oil seals, lubricate the oil seal lips with a light coat of lithium-soap-based grease. Oil bearings liberally when installing, if appropriate.

GEN

INFO

1 Oil seal

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 positioned opposite the thrust 3 that the circlip receives.

4 Shaft

1-3

CHECKING THE CONNECTIONS

EAS00026

CHECKING THE CONNECTIONS

Check the leads, couplers, and connectors for stains, rust, moisture, etc.

1. Disconnect:

8lead 8coupler 8connector

2. Check:

8lead 8coupler 8connector

Moisture J Dry with an air blower. Rust/stains J Connect and disconnect several times.

GEN

INFO

3. Check:

8all connections

Loose connection J Connect properly.

NOTE:

If the pin 1 on the terminal is flattened, bend it up.

4. Connect:

8lead 8coupler 8connector

NOTE:

Make sure all connections are tight.

5. Check:

8continuity

(with the pocket tester)

Pocket tester

90890-03132 (YU-03112-C)

NOTE:

8 If there is no continuity, clean the terminals.

When checking the wire harness, perform steps (1) to (3).

8 As a quick remedy, use a contact revitalizer

available at most part stores.

1-4

GEN

SPECIAL TOOLS

EAS00027

SPECIAL TOOLS

The following special tools are necessary for complete and accurate tune-up and assembly. Use only the appropriate special tools as this will help prevent damage caused by the use of inappropriate tools or improvised techniques. Special tools, part numbers or both may differ depending on the country. When placing an order, refer to the list provided below to avoid any mistakes.

INFO

Tool NO.

90890-01083(M6) YU-01083-1 90890-01085(M8) YU-01083-2 90890-01084 YU-01083-3

90890-01235 YU-01235

90890-01268 YU-01268

90890-01311 YM-08035-A

90890-01312 YM-01312-A

Tool name / Function Illustration

Rocker arm shaft puller bolt1

Weight2 These tools are used when removing or installing the rocker arm shafts.

Rotor holding tool

This tool is used to remove the flywheel magneto.

Ringnut wrench

This tool is used to loosen and tighten the exhaust and steering ring nut.

Valve adjusting tool

This tool is necessary for adjusting valve clearance.

Fuel level gauge

90890-01326 YM-01326 90890-01294 YM-01300-1

90890-01337 YM-33285 YM-33285-6

90890-01348 YM-01348

90890-01189 YM-01189

This gauge is used to measure the fuel level in the float chamber.

T-handle1 Damper rod holder2 These tool are used for holding the Damper rod holder when removing or installing the damper rod holder.

Clutch spring holder

These tool are used for removing the nut with holding the compression spring.

Lock nut wrench

This tool is used when removing or installing the secondary sheave nut.

Flywheel puller

This tool is used for removing the A.C. magneto rotor.

1-5

SPECIAL TOOLS

GEN

INFO

Tool NO.

90890-01367 YM-A9409-7 90890-01400 YM-A9409-3

90890-01384 YM-33299

90890-01403 YU-33975

90890-01701 YS-01880-A

90890-03079 YM-34483

Tool name / Function Illustration

Fork seal driver weight 1

Fork seal driver attachment(Ø30mm) 2 This tool is used when installing the fork seal.

Oil seal guide

This tool is used for protecting the oil seal lip when installing the secondary sliding sheave.

Ring nut wrench

This tool is used to loosen and tighten the steering ring nut.

Sheave holder

This tool is used for holding the secondary sheave.

Thickness gauge

90890-03081 YU-33223

90890-03132 YU-03112-C

90890-03113 YU-08036-C

90890-03141 YU-03141

90890-04019 YM-04019 90890-04108 YM-04108

This tool is used to measure the valve cleanance.

Compression gauge

These tool are used to measure the engine compression.

Pocket tester

This instrument is invaluable for checking the electrical system.

Engine tachometer

This tool is needed for detecting engine rpm.

Timing light

This tool is needed for detecting ignition timing.

Valve spring compressor Attachment(Ø19mm)

These tools are used when removing or installing the valve and the valve spring.

1-6

SPECIAL TOOLS

GEN

INFO

Tool NO.

90890-06754 YM-34487

90890-85505 ACC-11001-05-01

80890-04116 YM-04116

90890-04117 YM-04117

90890-04099 YM-04099

Tool name / Function Illustration

Ignition checker

This instrument is necessary for checking the ignition system components.

Yamaha bond NO.1215

This sealant (bond) is used for crankcase mating surface, etc.

Valve guide remover (4.5 mm)

This tool is used to remove or install the valve guides.

Valve guide installer (4.5 mm)

This tool is used to install the valve guides.

Valve guide reamer (5.0 mm)

This tool is used to rebore the new valve guides.

1-7

SPEC

CHAPTER 2

SPECIFICATIONS

GENERAL SPECIFICATIONS ................................................................. 2-1

ENGINE SPECIFICATIONS ..................................................................... 2-2

CHASSIS SPECIFICATIONS ................................................................. 2-11

ELECTRICAL SPECIFICATIONS .......................................................... 2-14

CONVERTION TABLE / GENERAL TIGHTENING TORQUE SPECIFICA-

TIONS ................................................................................................. 2-18

TIGHTENING TORQUES........................................................................ 2-19

ENGINE TIGHTENING TORQUES ................................................. 2-19

CHASSIS TIGHTENING TORQUES ............................................... 2-21

LUBRICATION POINTS AND LUBRICANT TYPES ............................. 2-22

ENGINE LUBRICATION POINTS AND LUBRICANT TYPES ....... 2-22

CHASSIS LUBRICATION POINTS AND LUBRICATION TYPES.. 2-24

OIL FLOW DIAGRAMS .......................................................................... 2-25

CABLE ROUTING .................................................................................. 2-27

2-31

GENERAL SPECIFICATIONS

SPECIFICATIONS

GENERAL SPECIFICATIONS

SPEC

Item

Model code 5YR1 (for USA) …

5YR2 (for CAN) …

Dimensions

Overall length 1755 mm (69.1 in) … Overall width 699 mm (27.5 in) … Overall height 1063 mm (41.8 in) … Seat height 759 mm (29.8 in) … Wheelbase 1230 mm (48.4 in) … Ground clearance 95 mm (3.8 in) … Minimum turning radius 1800mm (72 in) …

Weight

Wet (without oil and a full fuel tank) 109 kg (240 lb) … Dry (without oil and fuel) 104kg (229 lb) … Maximun load (total of cargo, rider, 253kg (558 lb) … passenger, and accessories)

Standard Limit

2-1

ENGINE SPECIFICATIONS

SPEC

Item

Standard Limit

Engine

Engine type Forced Air cooled 4-stroke, …

SOHC

Displacement 0.125L(125.0 cm

)… Cylinder arrangement Forward inclined single cylinder … Bore × stroke 51.5 × 60.0 mm … Compression ratio 9.8±0.4 :1 … Engine idle speed 1600~1700 r/min … Vacuum pressure at engine idle speed 30.0 kpa(238.6 mmHg) … Standard compression pressure (at sea level) 950 kPa(9.5kg/cm2) / 300 r/min …

Fuel

Recommended fuel Regular unleaded gasoline … Fuel tank capacity Total (including reserve) 4.5L (0.98lmp gal, 1.18 USgal) …

Engine oil

Lubrication system Wet sump …

Recommended oil

-20˚ -10˚ 0˚ 10˚ 20˚ 30˚ 40˚ 50˚

SAE 10W-30

SAE 10W-40

SAE 20W-40

SAE 20W-50

SAE20W40SE … Yamaha 4-cycle oil … EFERO X, Z, BX

Quantity Periodic oil change 1.0L(0.92 lmp qt, 1.09 US qt) … With oil filter replacement 1.2L(1.10 lmp qt, 1.31 US qt) … Total amount 1.2L(1.10 lmp qt, 1.31 US qt) …

Final gear oil

Recommended oil SAE85W140S Ehypoid gear oil … Periodic oil change 0.13L(0.12 lmp qt, 0.14 US qt) … Total amount 0.15L(0.14 lmp qt, 0.16 US qt) …

2-2

ENGINE SPECIFICATIONS

SPEC

Item

Oil filter

Oil filter type Wire mesh …

Oil pump

Oil pump type Trochoid … Inner rotor to outer rotor tip clearance 0.15 mm 0.23mm Outer rotor to pump housing clearance 0.013-0.036 mm 0.106mm Oil pump housing to inner rotor and outer 0.06-0.10 mm 0.17mm

rotor clearance

Starting system type Electric and kick starter …

Spark plug Model (manufacturer) × quantity CR7E (NGK) × 1 … Spark plug gap 0.7~0.8mm …

Cylinder head

Volume 12.3~12.7cm³ … Max. warpage … 0.03 mm

Standard

Limit

2-3

ENGINE SPECIFICATIONS

SPEC

Item

Camshaft

Drive system Chain drive (left) … Intake camshaft lobe dimensions

Measurement A 26.153~26.253 mm 26.053 mm Measurement B 21.015~21.115 mm 20.915 mm Measurement C 5.203mm … Exhaust camshaft lobe dimensions

Standard

Limit

Measurement A 26.153~26.253 mm 26.053 mm Measurement B 21.056~21.156 mm 20.956 mm Measurement C 5.203 mm … Max. camshaft runout … 0.03 mm

2-4

ENGINE SPECIFICATIONS

SPEC

Item

Standard

Limit

Timing chain

Model/number of links Morse 92RH2005 / 88 … Tensioning system Automatic …

Valve, valve seats, valve guides

Valve clearance (cold) Intake 0.08~0.12 mm … Exhaust 0.13~0.17 mm … Valve dimensions

Head Diameter Face Width Seat Width Margin Thickness

Valve head diameter A Intake 23.9~24.1 mm … Exhaust 20.9~21.1 mm … Valve face width B Intake 1.69~2.40 mm … Exhaust 1.69~2.40 mm … Valve seat width C Intake 0.9~1.1 mm 1.6mm Exhaust 0.9~1.1 mm 1.6mm Valve margin thickness D Intake 0.85~1.15 mm … Exhaust 0.85~1.15 mm … Valve stem diameter Intake 4.475~4.490 mm 4.445 mm Exhaust 4.460~4.475 mm 4.430 mm Valve guide inside diameter Intake 4.500~4.512 mm 4.550 mm Exhaust 4.500~4.512 mm 4.550 mm Valve stem to valve guide clearance Intake 0.010~0.037 mm 0.080 mm Exhaust 0.025~0.057 mm 0.100 mm Valve stem runout … 0.010 mm

Valve seat width Intake 0.9~1.1 mm 1.6mm Exhaust 0.9~1.1 mm 1.6mm

2-5

ENGINE SPECIFICATIONS

SPEC

Item

Valve springs

Free length Intake 37.30 mm 35.40 mm Exhaust 37.30 mm 35.40 mm Installed length (valve closed) Intake 25.77mm … Exhaust 25.77mm … Compressed spring force (installed) Intake 147±11N (15.0 ± 1.1 kgf/mm) … Exhaust 147±11N (15.0 ± 1.1 kgf/mm) … Spring tilt

Intake … 2.5°/1.6 mm Exhaust … 2.5°/1.6 mm Winding direction (top view) Intake Clockwise … Exhaust Clockwise …

Standard

Limit

Valve seat reformed Yes …

Cylinder

Cylinder arrangement Forward inclined single cylinder … Bore × stroke 51.5 × 60mm … Compression ratio 9.8 ± 0.4:1 … Bore 51.49~51.53 mm … Max. taper … 0.05 mm Max. out-of-round … 0.05 mm

2-6

ENGINE SPECIFICATIONS

SPEC

Item

Standard

Limit

Piston

Piston-to-cylinder clearance 0.010~0.030 mm 0.150mm Diameter D 51.470~51.510 mm …

Height H 3.5 mm … Piston pin bore (in the piston) Diameter 13.002~13.013 mm 13.043 mm Offset 0.35~0.65mm … Offset direction Intake side … Piston pin Outside diameter 12.996~13.000 mm 12.976 mm Piston rings Top ring

Ring type Barrel … Dimensions (B × T) 1.0 × 2.1mm … End gap (installed) 0.10~0.20 mm 0.45mm Ring side clearance 0.02~0.08 mm 0.13 mm 2nd ring

Ring type Plain … Dimensions (B × T) 1.0 × 2.1mm … End gap (installed) 0.20~0.30 mm 0.65mm Ring side clearance 0.02~0.06 mm 0.12mm Oil ring

Dimensions (B × T) 2.0 × 2.2 mm … End gap (installed) 0.2~0.7 mm … Ring side clearance 0.06~0.15 mm …

2-7

ENGINE SPECIFICATIONS

SPEC

Item

Rocker arm/rocker arm shaft

Rocker arm inside diameter 10~10.015mm … Rocker arm shaft outside diameter 9.981~9.991 mm … Arm-to-shaft clearance 0.009~0.034 mm …

Connecting rod

Connecting rod length 97.95~98.05 mm … Small end inside diameter 13.015~13.028mm …

Crankshaft

Width A 45.15~45.20 mm … Max. runout C … 0.03mm Big end side clearance D 0.10~0.40 mm 1.00mm Big end radial clearance E 0~0.010mm …

Standard

Limit

2-8

ENGINE SPECIFICATIONS

SPEC

Item

Clutch

Clutch type Automatic centrifugal … Clutch shoe thickness 3.4 ± 0.1 mm 2.0mm Clutch shoe spring free length 28.0 ± 0.4 mm … Clutch housing inside diameter 120 ± 0.1 mm 120.3mm Compression spring free length 113.6 mm … Weight outside diameter 20 ± 0.1 mm … Clutch-in revolution 3200±300 r/min … Clutch-stall revolution 5500±500 r/min …

V-belt

V-belt width 21.6 mm 19.5mm

Transmission

Transmission type V-belt automatic … Primary reduction system Helical gear … Primary reduction ratio 40/15 (2.667) … Secondary reduction system Spur gear … Secondary reduction ratio 38/13 (2.923) … Max. main axle runout … 0.02 mm Max. drive axle runout … 0.02 mm

Standard

Limit

Carburetor

Model (manufacturer) × quantity BS26 (MIKUNI) × 1 … ID mark 5YR 00 … Venturi tube bore Ø22.3 … Main jet #97.5 … Main air jet 0.5 … Jet needle 4D×16-1 … Needle jet 0-4M … Pilot air jet 1 160 … Pilot outlet 0.81 … Pilot jet 22.5 … Bypass 1 Ø0.8 … Bypass 2 Ø1.0 … Bypass 3 Ø1.1 … Valve seat size 2.0 … Starter jet 1 40 … Starter jet 2 0.8 … Throttle valve size 115 … Fuel level ( using fuel level gauge ) 6.5~7.5mm … Engine idle speed 1600~1700 r/min … CO% (air induction system ON) 0.2~1.4 % … CO% (air induction system OFF) 4.0~5.0 % … Oil temperature (°C) 70~80 °C …

2-9

ENGINE SPECIFICATIONS

SPEC

Item

Throttle bodys

Model (manufacturer) × quantity 5YR (SAFETY CONTROL …

CABLE) × 2 Intake vacuum pressure 30.0kpa (238.6mmHg) … Throttle cable free play (at the flange of the 3~5mm … throttle grip) ID mark 5YR1 …

Standard

Limit

2-10

CHASSIS SPECIFICATIONS

SPEC

Item

Frame

Frame type Steel tube underbone … Caster angle 32 ° … Trail 75 mm …

Front wheel

Wheel type Cast wheel … Rim Size 10 × MT2.15 … Material Aluminum … Wheel travel 59mm … Wheel runout Max. radial wheel runout … 1.0 mm Max. lateral wheel runout … 1.0 mm

Rear wheel

Wheel type Cast wheel … Rim Size 10 × MT2.15 … Material Aluminum … Wheel travel 54mm … Wheel runout Max. radial wheel runout … 1.0 mm Max. lateral wheel runout … 1.0 mm

Standard

Limit

Front tire

Tire type Tubeless … Size 3.50-10 51J … Model (manufacturer) C-922L (CHENG SHIN) … Tire pressure (cold) 0~90 kg 150kpa (1.5 kg/cm², 22 psi) … 90~197 kg 150kpa (1.5 kg/cm², 22 psi) … Min. tire tread depth … 0.8mm

Rear tire

Tire type Tubeless … Size 3.50-10 51J … Model (manufacturer) C-6007 (CHENG SHIN) … Tire pressure (cold) 0~90 kg 200kpa (2.0 kg/cm², 29 psi) … 90~197 kg 225kpa (2.25 kg/cm², 32 psi) … Min. tire tread depth … 0.8mm

2-11

CHASSIS SPECIFICATIONS

SPEC

Item

Front disc brake

Brake type Single disc brake … Operation Right-hand operation … Brake lever free play (at lever end) 3~5mm … Recommended fluid DOT 4 … Brake disc Diameter x thickness 180.0 × 4.0 mm 180.0 × 3.5 mm Min. thickness … 3.5mm Max. deflection … 0.10 mm Brake pad lining thickness-inner 6.0 mm 0.8mm Brake pad lining thickness-outer 6.0 mm 0.8mm Master cylinder inside diameter 11mm … Caliper cylinder inside diameter 34.93mm …

Standard

Limit

2-12

CHASSIS SPECIFICATIONS

SPEC

Item

Rear drum brake

Brake type Drum brake … Operation Left-hand operation … Brake lever free play (at lever end) 10~20mm … Brake drum inside diameter 110 mm 111mm Lining thickness 4.0mm 2mm

Front suspension

Suspension type Telescopic … Front fork type Coil spring/oil damper … Front fork travel 80 mm … Spring Free length 257.5 mm 252.4mm Installed length 245.5mm … Spring rate (K1) 12.7N/mm (1.27 kg/mm) … Spring stroke (K1) 0~50mm … Spring rate (K2) 19.6N/mm (1.96kg/mm) … Spring stroke (K2) 50~80mm … Optional spring available No … Fork oil Recommended oil Fork oil G10 or equivalent … Quantity (each front fork leg) 126 ± 2.5cc … Inner tube outer diameter 33 mm … Inner tube bending limit … 0.2 mm

Standard

Limit

Steering system

Steering bearing type Angular bearing … Lock to lock angle (left) 47.5 ° … Lock to lock angle (Right) 47.5 ° …

Rear suspension

Suspension type Swingarm … Rear shock absorber assembly type Coil spring/oil damper … Rear shock absorber assembly travel 65mm … Spring Free length 208mm … Installed length 198mm … Spring rate (K1) 43N/mm (4.3kg/mm) … Spring stroke (K1) 0~65mm … Optional spring available No …

2-13

ELECTRICAL SPECIFICATIONS

SPEC

Item

System voltage 12V … Ignition system Ignition system type C.D.I. … Ignition timing (B.T.D.C.) 5 °/1650 r/min (IDL) … Advancer type Digital … Pickup coil resistance /color 304~456 Ω / WR-WL … C.D.I. unit model (manufacturer) 5YR00(T-MORIC) …

Ignition coil

Model (manufacturer) 2JN (T-MORIC) … Minimum ignition spark gap 6mm … Primary coil resistance 0.184~0.276 Ω at 20 ° C … Secondary coil resistance 6.32~9.48 kΩ at 20 ° C …

Spark plug cap

Material Resin … Resistance 8~12 kΩ …

Charging system

System type C.D.I. magneto … Model (manufacturer) 5NW 01 (T-MORIC) … Nominal output 14V 120W / 5000 r/min … Lighting coil resistance /color 0.28~0.42 Ω/B-YR … Lighting coil resistance /color 0.32~0.48 Ω/B-W …

Standard

Limit

Voltage regulator

Regulator type Semiconductor, short circult … Model (manufacturer) SH671-12 (XIN DIAN YUAN) … No load regulated voltage(DC) 14~15 V …

Rectifier

Model (manufacturer) SH671-12 (XIN DIAN YUAN) … Rectifier capacity(DC) 8A … Withstand voltage 200V …

Battery

Battery type (manufacturer) GTX7A-BS (GS) … Battery voltage capacity 12V 6AH … Specific gravity 1.330 … Ten hour rate amperage 6 AH …

Headlight type Krypton bulb …

Indicator light

(voltage/wattage×quantity) Turn signal indicator light 12 V 1.7 W × 1 … High beam indicator light 14 V 3W × 1 …

2-14

ELECTRICAL SPECIFICATIONS

SPEC

Item

Bulbs (voltage/wattage × quantity)

Headlight 12 V 60 W/55 W × 1 … Tail/brake light 12 V 8W/27 W × 1 … Front turn signal light 12 V 10 W × 2 … Rear turn signal light 12 V 10 W × 2 … Speedometer light 14 V 3 W ×1 … Fuel lever meter light 14 V 3 W ×1 …

Standard

Limit

2-15

+ 264 hidden pages

YAMAHA YJ125S service manual

HOW TO USE THIS MANUAL

TABLE OF CONTENTS

SCOOTER IDENTIFICATION

IMPORTANT INFORMATION

CHECKING THE CONNECTIONS

SPECIAL TOOLS

GENERAL SPECIFICATIONS

ENGINE SPECIFICATIONS

CHASSIS SPECIFICATIONS

ELECTRICAL SPECIFICATIONS