Yamaha YSR50T User Manual

@YAM

AHA

Service

YS R5OT

SERVICE MANUAL

01987 by

unauthorized use without the written

permission of Yamaha Motor Corporation,

Yamaha Motor Corporation, U.S.A.

1st Edition, March 1987

U.S.A. is expressly prohibited.

Printed in U.S.A.

PINO. LIT-Il616-O6-05

NOTICE

This manual was written by the Yamaha Motor Company primarily for use by Yamaha dealers and

It

their qualified mechanics.

it

is assumed that persons using this book to perform maintenance and repairs on Yamaha motor-

so cycles have a basic understanding of the mechanical concepts and procedures inherent in motorcycle repair technology. Without such knowledge, attempted repairs or service to this model may render it

unfit to use andlor unsafe.

Yamaha Motor Company, Ltd. is continually striving to improve all models manufactured by Yamaha.

Modifications and significant changes in specifications or procedures will be forwarded to all Authorized

Yamaha dealers and will, where applicable, appear in future editions of this manual.

is not possible to put an entire mechanic's education into one manual,

HOW TO USE THIS MANUAL

PARTICULARLY IMPORTANT INFORMATION

This material is distinguished by the following notation.

NOTE:

MANUAL FORMAT

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

A CAUTION indicates special procedures that must be followed to avoid damage to the motorcycle.

A WARNING indicates special procedures that must be followed to avoid injury to a motorcycle operator or person inspecting or repairing the motorcycle.

TECHNICAL

MOTORCYCLE OPERATIONS YAMAHA MOTOR CO., LTD.

PU

BLlCATlONS

SERVICE DIVISION

All of the procedures in this manual are organized in a sequential, step-by-step format. The information has been compiled to provide the mechanic with an easy to read, handy reference that contains comprehensive explanations of all disassembly, repair, assembly, and inspection operations.

In this revised format, the condition of a faulty component will precede an arrow symbol and the course

of action required will follow the symbol, e.g.,

Bearings

Pitting1 Damage-, Replace.

EXPLODED DIAGRAM

Each chapter provides exploded diagrams before each disassembly section for ease in identifying cor-

rect disassembly and assembly procedures.

ILLUSTRATED SYMBOLS (Refer to the illustration)

I

ENG

1

Illustrated symbols thumb tabs to indicate the chapter's number and content.

a

General information

@

Specifications

@

Periodic inspection and adjustment

@

Engine

@

Cooling system

@

Carburetion

a

Chassis

@

Electrical

@

Troubleshooting

Illustrated symbols @ to @ are used to identify

the specifications appearing in the text.

@

Filling fluid Lubricant

@

Special tool

@

Tightening

@

Wear limit, clearance

@

Engine speed

@

9,

v,

A

@

to @ are designed as

Illustrated symbols

gram indicate grade of lubricant and location of

lubrication point.

0

Apply engine oil

@

Apply gear oil

8

Apply molybdenum disulfide oil

@

Apply wheel bearing grease Apply lightweight lithium-soap base grease

@

Apply molybdenum disulfide grease

@

Apply locking agent (LOCTITE@)

0

to @ in the exploded dia-

INDEX

GENERAL INFORMATION

SPECIFICATIONS

m

GEN

INFO

P

f

PERIODIC INSPECTION

AND ADJUSTMENT

ENGINE OVERHAUL

CHASSIS

em

INSP

ADJ

@

+o,

&O

ELECTRICAL

TROUBLESHOOTING

El

ELEC

0

IDLE SPEED ADJUSTMENT THROTTLE CABLE FREE PLAY ADJUSTMENT AUTOLUBE PUMP CABLE ADJUSTMENT AUTOLUBE PUMP STROKE ADJUSTMENT AUTOLUBE PUMP AIR BLEEDING SPARK PLUG INSPECTION IGNITION TIMING CHECK ENGINE OIL LEVEL CHECK TRANSMISSION OIL LEVEL INSPECTION TRANSMISSION OIL REPLACEMENT CLUTCH ADJUSTMENT AIR FILTER CLEANING CARBURETOR JOINT INSPECTOIN FUEL LINE INSPECTION Y.E.I.S. HOSE INSPECTION EXHAUST SYSTEM INSPECTION

...................................................

......................

.....................................................

...................................................

.....................................

....................

........................

.......................

................................

......................................

.....................................

........................

............................

........................................

..........................................

..............................

........................................

....................................

...............................

............

3.10

3.11

3.12

3.13

3.14

3.16

3.17

3-1

3.1

3.3 3-3

3.4

3.5

3.6

3.8

3.9

INFO

CHASSIS

FRONT BRAKE ADJUSTMENT REAR BRAKE ADJUSTMENT BRAKE FLUID INSPECTION BRAKE PAD INSPECTION BRAKE SHOE INSPECTION BRAKE LIGHT SWITCH ADJUSTMENT BRAKE HOSE INSPECTION DRIVE CHAIN SLACK ADJUSTMENT

DRIVE CHAIN LUBRICATION STEERING HEAD ADJUSTMENT

TIRE INSPECTION

WHEEL INSPECTION CABLE INSPECTION AND LUBRICATION LEVER AND PEDAL LUBRICATION SIDESTAND LUBRICATION

........................................................

..................................

...................................

....................................

......................................

.....................................

...................................

.............................................

...........................................

.....................................

..........................

...........................

................................

........................

.............................

3-17

3.17

3.18

3.19

3.20

3.21

3.23

3.24

3.25

ELECTRICAL

BATTERY INSPECTION FUSE INSPECTION HEADLIGHT BEAM ADJUSTMENT HEADLIGHT REPLACEMENT

.....................................................

.........................................

.............................................

3-26

3.26

3.28

..............................

....................................

3.29

CHAPTER

ENGINE

ENGINE REMOVAL

TRANSMISSION OIL

COWLING AND SIDE COVER FUEL TANK

MUFFLER CARBURETOR AUTOLUBE PUMP CABLE AND HOSE

LEADS CLUTCH CABLE

DRIVE CHAIN

ENGINE REMOVAL

ENGINE DISASSEMBLY

CYLINDER HEAD. CYLINDER AND PISTON CLUTCH AND PRIMARY DRIVE GEAR

KICK AXLE SHIFT SHAFT CDI MAGNETO CRANKCASE TRANSMISSION. SHIFTER AND CRANKSHAFT

......................................................

.........................................................

................................................

............................................

....................................................

..................................................

................................................

..................................................

..............................................

...........................................

.....................................................

..................................................

.................................................

..................................................

OVERHAUL

....................................

4

...........................

.

......................

..................

4-1 4-1 4-1 4-1 4-2 4-2

4.2 4-3

4.3 4-3

4.4

4.5

4.6 4-8 4-9 4-9

4-10

4.11

INSPECTION AND REPAIR

CYLINDER HEAD 4-13 CYLINDER AND PISTON 4.13 PISTON RINGS 4-15 PISTON PIN AND BEARING

rl

I

IT~U

...

w. . w..

SHIFT SHAFT TRANSMISSION AND SHIFTER CRANKSHAFT CRANKCASE AUTOLUBE PUMP

ENGINE ASSEMBLY AND ADJUSTMENT

CRANKSHAFT. SHIFTER AND TRANSMISSION CRANKCASE CDI MAGNETO SHIFT SHAFT

....

..............................................

................................................

L.

...................................................

.................................................

..................................................

.............................................

..................................................

................................................

.................................................

.......................................

....................................

.................................

........................

..................

4.13

4.16

4-17

"

4-19 4-20 4-21 4-22 4-22

4.24

4.24 4-25 4-30

4-32

KICK AXLE CLUTCH AND PRIMARY DRIVE GEAR CYLINDER HEAD. CYLINDER AND PISTON REMOUNTING ENGINE

....................................................

..........................

.........................................

4-32

4.34

..................... 4.37

4.40

CHAPTER

5

.

CARBURETION

CARBURETOR

REMOVAL DISASSEMBLY INSPECTION

INSTALLATION

ADJUSTMENT

REED VALVE

REMOVAL INSPECTION INSTALLATION

...................................................

......................................................

.................................................

....................................................

..................................................... ASSEMBLY 5-5

.................................................

..................................................

.....................................................

......................................................

....................................................

.................................................

CHAPTER

6

.

CHASSIS

FRONT WHEEL

REMOVAL 6-2 INSPECTION 6-2 INSTALLATION

....................................................

......................................................

....................................................

.................................................

-5-1 5-2 5-2

5.4

5.6 5-7

5-8 5-8 5-8

5.9

6-1

6-4

REAR WHEEL

REMOVAL 6.6 INSPECTION 6.6 INSTALLATION 6.8

FRONT BRAKE

BRAKE PAD REPLACEMENT 6.11 CALIPER DISASSEMBLY 6.13 MASTER CYLINDER DISASSEMBLY 6.14 INSPECTION AND REPAIR 6.15 ASSEMBLY

AIR BLEEDING 6-19

FRONT FORK

REMOVAL 6.21 DISASSEMBLY 6.21 INSPECTION 6.23

ASSEMBLY 6.23

INSTALLATION 6-26

.....................................................

......................................................

....................................................

.................................................

...................................................

...................................

.......................................

............................

......................................

....................................................

................................................

....................................................

.....................................................

................................................

...................................................

....................................................

................................................

6-5

6.10

6-16

6.20

STEERING HEAD AND HANDLEBAR

REMOVAL INSPECTION

l

NSTALLATION

.....................................................

...................................................

................................................

............................. 6.27

6-28

6-29

6.30

REAR SHOCK ABSORBER AND SWINGARM

REMOVAL DISASSEMBLY INSPECTION

ASSEMBLY

INSTALLATION

DRIVE CHAIN AND SPROCKETS

REMOVAL INSPECTION INSTALLATION

.....................................................

................................................

...................................................

....................................................

...............................................

................................. 6.38

..................................................... 6-38

...................................................

................................................

CHAPTER

7

.

ELECTRICAL

YSR50T CIRCUIT DIAGRAM

COLOR CODE

ELECTRICAL COMPONENTS

IGNITION AND STARTING SYSTEM

IGNITION CONTROL CIRCUIT OPERATION TROUBLESHOOTING

.................................................. 7-2

.......................................

......................................

...............................

............................................

....................

6.33 6-34 6-35 6-35 6-36

-6-36

6.38

6.39

7-1

7.3

7-4

....................... 7.6

7.7

CHARGING SYSTEM

TROUBLESHOOTING

LIGHTING SYSTEM

TROUBLESHOOTING (1) 7.24 TROUBLESHOOTING (2) 7.27

SIGNAL SYSTEM

TROUBLESHOOTING

DISPLAY SYSTEM

TROUBLESHOOTING TROUBLESHOOTING (2) DISPLAY SYSTEM TEST AND CHECK

.............................................

...........................................

...............................................

........................................

.................................................

........................................... 7.32

................................................

(1

)

........................................ 7.44

........................................

...........................

CHAPTER

8

.

TROUBLESHOOTING

STARTING FAILUREIHARD STARTING

FUEL SYSTEM ELECTRICAL SYSTEM COMPRESSION SYSTEM

.................................................

...........................................

........................................

............................

7.16

7.18

7.22

7.30

7.42

7.48

7.50

8.1

8.2

8.3

POOR IDLE SPEED PERFORMANCE

...............................

..............................

8.3

POOR MEDIUM AND HIGH SPEED PERFORMANCE

FUEL SYSTEM ELECTRICAL SYSTEM COMPRESSION SYSTEM

FAULTY GEAR SHIFTING

HARD SHIFTING

CHANGE PEDAL DOES NOT MOVE

JUMP-OUT GEAR

CLUTCH SLIPPINGIDRAGGING

CLUTCH SLIPPING

CLUTCH DRAGGING

IMPROPER KICKING

SLIPPING HARD KICKING KICK CRANK NOT RETURNING

FAULTY BRAKE

POOR BRAKING EFFECT

.................................................

...........................................

........................................

.........................................

................................................

..............................

...............................................

...................................

..............................................

............................................

..............................................

......................................................

.................................................

.................................

...................................................

........................................

..............

8.4

8.5

8.6 8-6

pqm

INFO

8-6 8-6

8.7

8.7 8-7

8-8 8-8

8-8

8.8

8-9

8.9

FRONT FORK OIL LEAKAGE AND FRONT FORK MALFUNCTION

OIL LEAKAGE MALFUNCTION

INSTABLE HANDLING

FAULTY SIGNAL AND LIGHTING SYSTEM

HEADLIGHT DARK

BULB BURNT OUT FLASHER DOES NOT LIGHT FLASHER KEEPS ON

FLASHER WINKS SLOWER FLASHER WINKS QUICKER HORN IS INOPERATIVE

OVERHEATING

YSR5OT WIRING DIAGRAM

..................................................

.................................................

........................................... 8.10

.........................................

.......................

.............................................

............................................

...................................

.......................................... 8.11

....................................

........................................

...................................................

................................................

.... 8.9

8-9 8-9

8.10

8.11 8-11

8.11

8.12

8.13 8-13

your state.

IAL

N

The engine serial num

sf

the

left side

en

::.

cThe first three di ts sf these numbers are for

ns;

%he

model identificat

duction number.

specifications are su

without notice.

remainin

-

IMPORTANT INFORMATION

PREPARATION FOR REMOVAL AND DISASSEMBLY

1.

Remove all dirt, mud, dust, and foreign

material before removing and disassembling.

2.

Use proper tools and cleaning equipment. Refer to "SPECIAL TOOL."

I

1-1

3.

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

4.

During the motorcycle disassembly, clean all

parts and place them in trays in the order of

disassembly. This will speed up assembly time

and help assure that all parts are correctly rein-

stalled.

5.

Keep away from fire.

IMPORTANT INFORMATION

ALL REPLACEMENT PARTS

1.

We recommend to use Yamaha genuine parts for all replacements. Use oil and/or grease

recommended by Yamaha for assembly and

adjustment.

GASKETS, OIL SEALS, AND O-RINGS

1.

All gaskets, seals and O-rings should be replaced when an engine is overhauled. All gasket surfaces, oil seal lips and O-rings must be cleaned.

2.

Properly oil all mating parts and bearings during reassembly. Apply grease to the oil seal lips.

PI

LOCK WASHERSIPLATES AND COlTER PINS

1.

All lock washers1Plates @ and cotter pins must be replaced when they are removed. Lock tab(s) should be bent along the bolt or nut flat(s) after the bolt or nut has been properly tightened.

BEARINGS AND OIL SEALS

1.

Install the bearing(s1 and oil seal(s) with their

manufacturer's marks or numbers facing outward. (In other words, the stamped letters must be on the side exposed to view. When installing oil light-weight lithium base grease to the seal lip(s). Oil the bearings liberally when installing.

@

Oil

seal

seal(s), apply a light coating of

Do not use compressed air to spin the bearings dry. This causes damage to the bearing

surfaces.

@

Bearing

SPEClAL TOOLS

ClRCLlPS

1.

All circlips should be inspected carefully before reassembly. Always replace piston pin

clips after one use. Replace distorted circlips. When installing a circlip the sharp edged corner

posite to the thrust sectional view.

@I

Shaft

-1

@,

make sure that

@

is

positioned op-

@

it receives. See the

SPECIAL TOOLS

The proper special tools are necessary for complete and accurate tune-up and assembly. Using the correct special tool will help prevent damage

caused by the use of improper tools or improvised

techniques.

FOR

TUNE

1.

Inductive Timing Light

PIN.

This tool is necessary for adjusting ignition timing.

2.

Fuel Level Gauge

PIN.

UP

YM-33277

YM-01312

This gauge is used to measure the fuel level in

the float chamber.

1-4

3.

Inductive Tachometer

YU-08036

PIN.

This tool is needed for detecting engine rpm.

FOR ENGINE SERVICE

1.

Universal Clutch Holder

YM-91042

PIN.

This tool is used to hold the clutch when loosening or tightening the clutch boss locknut.

2.

Universal Rotor Holder

YU-01235

PIN.

This tool is used when loosening or tightening the

flywheel magneto securing bolt.

3.

Flywheel Puller

YM-01189

PIN.

This tool is used for removing the flywheel.

4.

Piston Pin Puller

YU-01304

PIN.

This tool is used to remove the piston pin.

SPECIAL

5.

Crankcase Separating Tool PIN.

This tool is used to split the crankcases as well as remove the crankshaft from either case.

TOOLS

YU-01135

wl

6.

Crankshaft Installing Tool

PIN.

YU-90050

Adapter

PIN.

These tools are used to install the crankshaft.

FOR

CHASSIS SERVICE

1.

Front Fork Seal Driver (Weight)

PIN. Adapter

PIN.

............................

YM-90063

YM-33963

..........................

YM-33281

.............

0 0

.....

This tool is used when installing the fork seal.

2.

Ring Nut Wrench

YU-33975

PIN.

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

1-6

GEN

SPECIAL TOOLS

FOR

ELECTRICAL COMPONENTS

1.

Coil Tester

YU-33261

PIN.

This tester is necessary for checking the ignition system components.

2.

Pocket Tester

YU-03112

PIN.

This tester is invaluable for checking the electrical system.

wl

GENERAL SPECIFICATIONS

SPECIFICATIONS

GENERAL SPECIFICATIONS

Model Model Code Number: Vehicle Identification Number: Engine Starting Number Dimensions:

Overall Length Overall Width Overall Height Seat Height Wheel base Minimum Ground Clearance

Basic Weight:

With Oil and Full Fuel Tank

1,630 mm (64.2 in)

635 mm (25.0 in) 930 mm (36.6 in) 660 mm (26.0 in)

1,055 mm (41.5 in)

120 mm (4.7 in)

I

SPEC

/

pf

I

Minimum Turning Radius: Engine:

Engine Type Induction System Cylinder Arrangement Displacement

x

Bore Compression Ratio Starting System

Lubrication System:

TY pe

Engine Oil Type

Transmission Oil Type

Oil Capacity:

Engine Oil (Oil Tank)

Transmission Oil:

Stroke

Periodic Oil Change

Total Amount

2,400 mm (94.5 in)

Air cooled 2-stroke Reed valve Forward inclined single cylinder

49.3 cm3

x

40.0

7.4 Kick starter

Separate lubrication (Yamaha Autolube)

0.73

0.60 L (0.53 Imp qt, 0.63 US qt)

0.65

39.2 mm (1.57 x 1.54 in)

:

1

Yamalube "BIA certified for service TC-W" Yamalube

"GL"

"2

or air cooled 2 stroke engine oil with

"4,

SAE 10W30 type SE motor oil or

gear oil

L

(0.64 Imp qt, 0.77 US qt)

L

(0.57 Imp qt, 0.69 US qt)

Air Filter

Type

Wet type element

Model

Fuel:

TY pe Fuel Tank Capacit

Full Amount Reserve Amount

Carburetor:

Type/ Quantity Manufacturer

Spark Plug:

TypeIQuantity Manufacturer Plug Gap

Clutch:

Type

Transmission:

TY pe Primary Reduction System

Primary Reduction Ratio Secondary Reduction System Secondary Reduction Ratio Operation Gear Ratio

1 st 2nd 3rd 4th 5th

I

GENERAL SPECIFICATIONS

Regular gasoline

8.0 L (1.76 Imp gal, 2.1 1 US gal)

1.5 L (0.33 Imp gal, 0.39 US gal)

VM16SH/1 pc.

MIKUNI

B7HS or B8HS NGK

-

0.6 mm (0.020 - 0.024 in)

0.5

Wet, multiple disc

Constant mesh 5-speed Helical gear 68/19 (3.579) Chain drive 44/12 (3.667) Left foot operation

I

SPEC

/

pf

I

Chassis:

Frame Type Caster Angle

Trail

Tire:

TY pe Size

Front

Rear

Tire Pressure (Cold Tire):

Basic Weight:

With Oil and Full Fuel Tank

Maximum Load*

Cold Tire Pressure:

-

Zero

*

Load is total weight of cargo, rider, and accessories.

Maximum Load*

Double cradle

25.3' 64 mm (2.52 in)

Tubeless

3.50-12 2PR

4.00-12 2PR

FRONT

2-2

Model

Brake:

Front Brake Type Front Brake Operation Rear Brake Type

Rear Brake Operation

Suspension:

Front Suspension Type

Rear Suspension Type

Shock Absorber:

Front Shock Absorber Rear Shock Absorber

Wheel Travel:

Front Wheel Travel Rear Wheel Travel

Electrical:

Ignition System

Generator System

GENERAL SPECIFICATIONS

Single disc brake Right hand operation Drum brake Right foot operation

Telescopic fork

Swingarm (Monocross suspension)

Coil springloil damper Coil springloil damper

90 mm (3.5 in)

75

mm (3.0 in)

CDI Magneto Flywheel magneto

-1

Battery:

Type Capacity

Headlight:

TY pe

Bulb Wattage (Quantity):

Headlight

TailIBrake Light

Flasher Light Licence Light Meter Light "NEUTRAL" lndicator Light "HIGH BEAM" lndicator Light "TURN" lndicator Light

"OIL" Warning lndicator Light

(Light Emitting Diode)

Sealed beem

MAINTENANCE SPECIFICATIONS

ENGINE

Model

I

SPEC

1

p9

I

Cylinder Head:

Warpage Limit

Cylinder:

Bore Size

Taper Limit

Out of Round Limit

Piston:

Piston Size Measuring Point "a"

Piston Off-Set Piston-to-Cylinder Clearance

<

Limit Oversize Oversize

"D"

>

1st

2nd

*

0.02 mm (0.001 in) "Lines indicate straightedge measurement.

40.00-40.02 mm (1.575- 1.576 in)

0.05 mm (0.002 in)

0.01 mm (0.0004 in)

39.96-39.98 mm (1.573- 1.574 in)

5 mm (0.20 in)

0.2 mm (0.008 in)

-

0.030

<

40.25 mm (1.58 in)

40.50 mm (1.59 in)

0.035 mm (0.0012 - 0.0014 in)

0.1 mm (0.004 in)

>

Piston Ring:

Sectional Sketch Top Ring

OTg

LT~

End Gap (Installed) Top Ring

2nd Ring

Side Clearance Top Ring

2nd Ring

Keystone type B = 1.2 mm (0.047 in)

=

1.6 mm (0.063 in)

T

Plain type B

=

1.2 mm (0.047 in)

=

1.6 mm (0.063 in)

T

-

0.15

0.15-0.35 mm (0.006-0.014 in)

0.03-0.05 mm (0.001 -0.002 in)

0.35 mm (0.006 - 0.014 in)

MAINTENANCE SPECIFICATIONS

Model

Crankshaft:

Crank Width "A" Runout Limit "B" Big End Side Clearance "C"

<

Limit

>

Small End Free Play "D"

<

Limit

>

-

Clutch: Friction Plate:

Thickness

Quantity

Wear Limit

Clutch Plate:

Thickness

Quantity

Warpage Limit

Clutch Spring:

Free Length Quantity Minimum Free Length

Clutch Release Method

<

Push Rod Bending Limit

D

>

I

SPEC

37.90-37.95 mm (1.492- 1.494 in)

0.03 mm (0.0012 in)

-

0.2- 0.7 mm (0.008

<

1.0 mm (0.04 in)

0.8- 1.0 mm (0.032-0.039 in)

<

1.5 mm (0.06 in)

3.5 mm (0.138 in) 2 pcs.

2.7 mm (0.106 in)

2.0 mm (0.079 in) PC.

1

0.05 mm (0.002 in)

28.2 mm (1.11 in)

4 pcs.

26.2 mm (1.03 in) Inner push, cam push

~0.2 mm (0.008 in)

0.028 in)

> >

>

1

pp

I

Transmission:

Main Axle Runout Limit Drive Axle Runout Limit

Shifter:

TY pe Guide Bar Bending Limit

Kick Starter:

TY pe

-

0.08 mm (0.003 in)

Cam drum and guide bar

0.025 mm (0.001 in)

Kick and Mesh type

Air Filter:

Oil Grade

Carburetor:

I.D. Mark

Main Jet Air Jet Jet Needle-Position

Needle Jet

Cutaway

Pilot Outlet

Pilot Jet Air Screw Valve Seat Size Starter Jet

Fuel Level

Float Height

Idling Speed

Model

MAINTENANCE SPECIFICATIONS

Foam-Air-Filter oil or Yamalube

2AL 01

#

120

42.5

3621 -4

E-0

2.0

40.9

#

17.5

1-118

41.5

#

20

0- 1

mm (0- 0.04 in)

21 -23 mm (0.83 - 0.91 in) 1,300 - 1,400 rlmin

-1

"2"

Reed Valve:

Valve Thickness Valve Stopper Height Valve Bending Limit

Lubrication System:

Autolube Pump

Color Code Minimum Stroke Maximum Stroke Minimum Output Maximum Output

Pulley Adjusting Mark

0.15 mm (0.006 in)

6.7-7.3 mm (0.26- 0.29 in)

0.3 mm (0.012 in)

Green

0.20 - 0.25 mm (0.008 - 0.010 in)

1.85-2.05 mm (0.073-0.081 in)

0.50-0.63 cm3 per 200 strokes

4.64 - 5.15 cm3 per 200 strokes

At idle

TIGHTENING TORQUE

MAINTENANCE SPECIFICATIONS

I

SPEC

/

p9

I

Part to be tightened

Spark plug Cylinder head Autolube pump Intake manifold Muffler (Front) Muffler (Rear) Crankcase Crankcase cover Transmission oil drain bolt Autolube pump cover Kick crank assembly Primary drive gear Clutch boss Pressure plate Stopper plate (Bearing) Stopper plate (Shift cam) Shift lever adjuster nut Change pedal Stator CDI magneto Neutral switch

BoltINut

size

Tightening torque

MAINTENANCE SPECIFICATIONS

CHASSIS

Model

Steering System:

Bearing Type Bearing Size (Quantity)

Upper Lower

Front Suspension:

Front Fork Travel Fork Spring Free Length (Left side only)

<

Limit

>

Spring Rate (K1) Stroke (KI) Optional Spring

pi+q

Ball Bearing

90 mm (3.54 in)

374.2 mm (14.7 in) <367 mm (14.4 in)

8.2 Nlmm (0.83 kglmm, 46.6 Iblin)

0.0-90.0 mm (0.0 -3.5 in)

No.

>

Oil Capacity

Oil Level

Oil Grade

3ear Suspension:

Shock Absorber Travel Spring Free Length Fitting Length Spring Rate Stroke (K1) Optional Spring

Swingarm:

Free Play Limit (Swingarm end)

Front Wheel:

TY pe

Rim Size Rim Material Rim Runout Limit

Vertical

Lateral

(K1)

LEFT

126 cm3 (4.44 Imp oz,

4.26 US oz)

146 mm (5.74 in)

From top of inner tube fully compressed without spring.

Yamaha fork oil 10WT or

equivalent

18.0 mm (0.71 in) 86 mm (3.4 in) 82 mm (3.2 in) 353 Nlmm (36 kglmm, 2,020 Iblin)

0.0- 18 mm (0.0-0.71 in)

No.

1.0 mm (0.039 in) Move

swingarm end side to side

Panel wheel MT2.50 Steel

2.0 mm (0.08 in)

x

12

164 cm3 (5.77 Imp oz,

5.54 US oz) 51 mm (2.01 in)

From top of inner tub( compressed without spring.

t

RIGHT

MAINTENANCE SPECIFICATIONS

pqi$q

I

Rear Wheel:

Type

Rim Size Rim Material Rim Runout Limit

Vertical

Lateral

Drive Chain:

Type! Manufacturer

Number of Links Chain Free Play

Front Disc Brake:

TY pe

Disc Outside Diameter Disc Thickness Pad Thickness

<Wear Limit Master Cylinder lnside Diameter Caliper Cylinder lnside Diameter Brake Fluid Type

Model

>

Panel wheel MT2.50

Steel

2.0 mm (0.08 in)

420M/ DAIDO 99 Links +joint 25-30 mm (1.0- 1.2 in)

Single

203 mm (8.00 in)

4.0 mm (0.16 in)

6.0 mm (0.24 in)

<

11

34.9 mm (1.37 in) DOT No.

x

12

0.5 mm (0.02 in)

.O

mm (0.433 in)

3

>

Rear Drum Brake:

TY pe Brake Drum lnside Diameter

<

Limit

>

Shoe Spring Free Length

Lining Thickness

<

Limit

>

Brake Lever and Brake Pedal:

Brake Lever Free Play

Brake Pedal Free Play

Clutch Lever Free Play

Throttle Cable Free Play

Leading, Trailing 110 mm (4.33 in)

<

11 1 mm (4.37 in)

50.5 mm (1.99 in)

4

mm (0.16 in)

<2 mm (0.08 in)>

2-5 mm (0.08-0.20 in)

20-30 mm (0.8-1.2 in)

Below top of footrest

2-3 mm (0.08-0.12 in)

3-7 mm (0.12-0.28 in)

At grip flange

>

MAINTENANCE SPECIFICATIONS

TIGHTENING

Chassis:

Engine mounting;

Engine stay

Frame and engine Pivot shaft and nut Rear shock absorber and frame Front fork cap bolt (Handlebar) Under bracket and inner tube Steering ring nut

Steering stem bolt

Wheel hub and wheel rim

Front brake disc and wheel hub Brake caliper and outer tube Front wheel axle and nut Brake cam lever and camshaft Rear wheel sprocket and wheel hub

Tension bar and

Rear wheel axle and nut Rear view mirror and stay Brake hose union bolt Footrest and frame

Cowling stay and frame Windscreen and cowling CDI unit and frame Rectifier1 Regulator Down tube and frame Engine bracket (Front) and frame Engine bracket (Rear) and frame

TORQUE

Part to be tightened

platelframe

BoltlNut size

Tightening torque

ft-lb

Refer to NOTE

NOTE:

1.

First, tighten the ring nut approximately 30 Nm (3.0 m-kg,

then loosen the ring nut one turn.

2.

Retighten the ring nut to specification.

22

ft-lb) by using the torque wrench,

Yamaha YSR50T User Manual

CONTENTS