Yamaha YFM350 User Manual

YFM350S

3GD-AE7

SUPPLEMENTARY

SERVICE MANUAL

FOREWORD

This Supplementary Service Manual has been prepared to introduce new service and data for the YFM350S. For complete service information procedures it is necessary to use this Supplementary Service Manual together with the following manual.

YFM350X(J) ’97 SERVICE MANUAL: 3GD-AE5

YFM350X(P) 2002 SUPPLEMENTARY SERVICE MANUAL: 3GD-AE6

YFM350S SUPPLEMENTARY SERVICE MANUAL

First edition, January 2004

Any reproduction or unauthorized use

without the written permission of

Yamaha Motor Co., Ltd. is expressly prohibited.

EBS00002

NOTICE

This manual was produced by the Yamaha Motor Company 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, so it is assumed that anyone who uses this book to perform maintenance and repairs on Yamaha machine has a basic understanding of the mechanical ideas and the procedures of machine repair. Repairs attempted by anyone without this knowledge are likely to render the machine unsafe and unfit for use.

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

EBS00003

IMPORTANT INFORMATION

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

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

WARNING

CAUTION:

NOTE:

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

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

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

EBS00004

HOW TO USE THIS MANUAL

MANUAL ORGANIZATION

This manual consists of chapters for the main categories of subjects. (See “symbols”) 1st title 1: This is the title of the chapter with its symbol in the upper right corner of each page. 2nd title 2: This title indicates the section of the chapter and only appears on the first page of each section. It is located in the upper left corner of the page. 3rd title 3: This title indicates a sub-section that is followed by step-by-step procedures accompanied by corresponding illustrations.

EXPLODED DIAGRAMS

To help identify parts and clarify procedure steps, there are exploded diagrams at the start of each removal and disassembly section.

1. An easy-to-see exploded diagram 4 is provided for removal and disassembly jobs.

2. Numbers 5 are given in the order of the jobs in the exploded diagram. A number that is enclosed by a circle indicates a disassembly step.

3. An explanation of jobs and notes is presented in an easy-to-read way by the use of symbol marks

. The meanings of the symbol marks are given on the next page.

4. A job instruction chart 7 accompanies the exploded diagram, providing the order of jobs, names of parts, notes in jobs, etc.

5. For jobs requiring more information, the step-by-step format supplements 8 are given in addition to the exploded diagram and the job instruction chart.

GEN

INFO

SPEC

CHK

ADJ

CARB

ENG

CHAS

EB003000

ILLUSTRATED SYMBOLS

Illustrated symbols 1 to 8 are printed on the top right of each page and indicate the subject of each chapter.

General information

Specifications

Periodic checks and adjustments

Engine

Carburetion

Chassis

Electrical

Troubleshooting

– +

TRBL

ELEC

SHTG

FGH

Illustrated symbols 9 to E are used to identify the specifications appearing in the text.

Filling fluid

Lubricant

Special tool

Torque

Wear limit, clearance

Engine speed

, V, A

Ω

Illustrated symbols F to L in the exploded diagrams indicate the types of lubricants and lubrication points.

New

JKL

Apply engine oil

Apply gear oil

Apply molybdenum disulfide oil

Apply wheel bearing grease

Apply lightweight lithium soap base grease

Apply molybdenum disulfide grease

Apply silicon grease

Illustrated symbols M to N in the exploded diagrams indicate where to apply a locking agent M and when to install a new part N.

Apply the locking agent (LOCTITE

Replace

)

CONTENTS

GENERAL INFORMATION

MACHINE IDENTIFICATION ....................................................................... 1

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

SPECIAL TOOLS ......................................................................................... 2

SPECIFICATIONS

GENERAL SPECIFICATIONS .....................................................................3

MAINTENANCE SPECIFICATIONS ............................................................ 5

ENGINE .................................................................................................5

CHASSIS ...............................................................................................7

ELECTRICAL.......................................................................................10

CABLE ROUTING ...................................................................................... 11

PERIODIC CHECKS AND ADJUSTMENTS

INTRODUCTION ........................................................................................ 23

PERIODIC MAINTENANCE/LUBRICATION..............................................23

SEAT, FENDERS AND FUEL TANK.......................................................... 25

SEAT, SIDE COVERS, AND FRONT PANEL .....................................25

FOOT PROTECTORS, ENGINE SKID PLATE,

AND FRONT BUMPER....................................................................... 26

HEADLIGHTS AND FRONT FENDER ................................................ 27

REAR FENDER ................................................................................... 28

FUEL TANK ......................................................................................... 30

CHASSIS.................................................................................................... 32

CHECKING THE FRONT BRAKE PADS............................................. 32

ADJUSTING THE PARKING BRAKE .................................................. 32

ADJUSTING THE REAR SHOCK ABSORBER................................... 33

ELECTRICAL SYSTEM.............................................................................. 35

CHECKING AND CHARGING THE BATTERY ................................... 35

ADJUSTING THE HEADLIGHT BEAMS .............................................40

REPLACING A HEADLIGHT BULB..................................................... 41

..............................................................................................3

................................................................................1

.................................................... 23

ENGINE

CARBURETOR

............................................................................................................42

ENGINE REMOVAL ................................................................................... 42

INSTALLING THE ENGINE ................................................................. 42

CLUTCH .....................................................................................................43

INSTALLING THE RIGHT CRANKCASE COVER............................... 43

.................................................................................................44

CARBURETOR .......................................................................................... 44

CHASSIS .......................................................................................................... 47

REAR WHEELS AND REAR AXLE HUB ................................................... 47

REMOVING THE REAR AXLE ............................................................ 49

INSTALLING THE REAR AXLE........................................................... 50

FRONT ARMS AND FRONT SHOCK ABSORBER ................................... 51

REAR BRAKE ............................................................................................ 53

ASSEMBLING THE REAR BRAKE CALIPER ..................................... 53

REAR SHOCK ABSORBER AND SWINGARM ......................................... 54

HANDLING THE REAR SHOCK ABSORBER

AND GAS CYLINDER......................................................................... 56

DISPOSING OF THE REAR SHOCK ABSORBER

AND GAS CYLINDER......................................................................... 56

ELECTRICAL ...................................................................................................57

ELECTRICAL COMPONENTS................................................................... 57

YFM350S WIRING DIAGRAM

MACHINE IDENTIFICATION

GENERAL INFORMATION

MACHINE IDENTIFICATION

MODEL LABEL

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

GEN

INFO

– 1 –

GEN

SPECIAL TOOLS

EB102001

SPECIAL TOOLS

The following special tools are necessary for complete and accurate tune-up and assembly. Use only the appropriate special tools; this will help prevent damage caused by the use of inappropriate tools or improvised techniques. Special tools may differ by shape and part number from country to country. In such a case, two types are provided. When placing an order, refer to the list provided below to avoid any mistakes.

For US and CDN

P/N. YM-, YU-, YS-, YK-, ACC-

Except for US and CDN

P/N. 90890-

Tool No. Tool name/How to use Illustration

Steering nut wrench

90890-01443

YU-33975

This tool is needed to loosen and tighten the rear shock absorber locknut.

INFO

90890-01498

YM-37134

Axle nut wrench (46 mm)

This tool is needed to loosen or tighten the rear axle nut.

– 2 –

GENERAL SPECIFICATIONS

SPECIFICATIONS

GENERAL SPECIFICATIONS

Model YFM350S

SPEC

Model code number

Dimensions

Overall length 1,770 mm (69.7 in) Overall width 1,095 mm (43.1 in) Overall height 1,080 mm (42.5 in) Seat height 820 mm (32.3 in) Wheelbase 1,210 mm (47.6 in) Minimum ground clearance 115 mm (4.53 in)

Basic weight

With oil and full fuel tank 180.0 kg (397 lb)

Minimum turning radius Engine

Engine type Air-cooled 4-stroke, SOHC Cylinder arrangement Forward-inclined single cylinder Displacement 349.0 cm Bore × stroke 83.0 × 64.5 mm (3.27 × 2.54 in) Compression ratio 9.20 : 1 Compression pressure 850 kPa (8.5 kg/cm Starting system Electric starter

Oil capacity

Engine oil

Periodic oil change 2.50 L (2.20 Imp qt, 2.64 US qt) With oil filter replacement 2.60 L (2.29 Imp qt, 2.75 US qt) Total amount 3.20 L (2.82 Imp qt, 3.38 US qt)

Fuel

Type Regular unleaded gasoline only

Tank capacity 9.0 L (1.98 Imp gal, 2.38 US gal) Reserve amount 2.7 L (0.59 Imp gal, 0.71 US gal)

Carburetor

Type/manufacturer BSR36/MIKUNI

5YT1 (For USA and Oceania) 5YT2 (For CDN) 5YT3 (For Europe)

3,100 mm (122 in)

(21.30 cu.in)

, 120.9 psi) at 350 r/min

(For CDN and Europe) Unleaded gasoline only (For USA and Oceania)

– 3 –

GENERAL SPECIFICATIONS

Model YFM350S

Transmission

Primary reduction system Spur gear Primary reduction ratio 76/24 (3.167) Secondary reduction system Chain drive Secondary reduction ratio 38/13 (2.923) Transmission type Constant mesh, 6-speed forward, 1-speed

reverse Operation Left foot operation Gear ratio 1st 36/16 × 20/27 × 29/18 (2.685)

2nd 33/20 × 20/27 × 29/18 (1.969) 3rd 29/23 × 20/27 × 29/18 (1.504) 4th 27/26 × 20/27 × 29/18 (1.239) 5th 25/28 × 20/27 × 29/18 (1.066) 6th 23/29 × 20/27 × 29/18 (0.946) Reverse 33/16 × 33/10 (6.806)

Chassis

Frame type Steel tube frame Caster angle 6° Trail 26.0 mm (1.02 in) Toe-in (unloaded) 20 ~ 30 mm (0.79 ~ 1.18 in)

Tires

Type Tubeless Size front AT21 × 7-10

rear AT20 × 10-9

Manufacturer front DUNLOP

rear DUNLOP

Type front KT851B

rear KT877A

Brakes

Front brake type Dual disc brake

operation Right hand operation

Rear brake type Single disc brake

operation Right foot operation

Electrical

Ignition system DC C.D.I. Generator system A.C. magneto Battery voltage/capacity 12 V/8.6 Ah Battery type YTZ10S

Bulb wattage × quantity

Headlight 12 V 30 W/30 W × 2 Tail/brake light 12 V 5 W/21 W × 1 Neutral indicator light 12 V 1.7 W × 1 Reverse indicator light 12 V 1.7 W × 1

SPEC

– 4 –

MAINTENANCE SPECIFICATIONS

SPEC

MAINTENANCE SPECIFICATIONS

ENGINE

Model YFM350S

Rocker arm/rocker arm shaft

Rocker arm inside diameter 11.980 ~ 11.998 mm (0.4717 ~ 0.4724 in) Rocker arm shaft outside diameter 11.961 ~ 11.971 mm (0.4709 ~ 0.4713 in) Rocker-arm-to-rocker-arm-shaft clearance 0.009 ~ 0.037 mm (0.0004 ~ 0.0015 in)

Carburetor

I.D. mark 5YT1 00 Main jet (M.J) #142.5 Main air jet (M.A.J) #35 Jet needle (J.N) 5JFC39-2 Needle jet (N.J) P-0M Pilot jet (P.J) #22.5 Pilot air jet (P.A.J.1) #65

(P.A.J.2) #165 Pilot outlet (P.O) 1 Bypass 1 (B.P.1) 0.8 Bypass 2 (B.P.2) 0.8 Bypass 3 (B.P.3) 0.8 Pilot screw turns out (P.S) 2-1/4 (For CDN, Europe, and Oceania) Valve seat (V.S) 2.5 Starter jet (G.S) #70 Throttle valve size (Th.V) #105 Fuel level (F.L) 4 ~ 5 mm (0.16 ~ 0.20 in)

Above the float chamber mating surface Float height 13.0 mm (0.51 in) Engine idling speed 1,450 ~ 1,550 r/min Intake vacuum 33.3 kPa (250 mmHg, 9.83 inHg)

– 5 –

Tightening torques

MAINTENANCE SPECIFICATIONS

SPEC

Part to be tightened Part name

Carburetor joint Bolt M8 2 20 2.0 14 Carburetor clamp (cylinder head side) Screw M4 1 3 0.3 2.2 Carburetor clamp (air filter case side) Screw M4 1 3 0.3 2.2 Air filter case Screw M4 1 3 0.3 2.2 Muffler and exhaust pipe Bolt M8 1 16 1.6 11 Muffler Bolt M8 2 34 3.4 24 Clutch cable holder Bolt M8 1 16 1.6 11 Right crankcase cover Bolt M6 15 10 1.0 7.2 Left crankcase cover Bolt M6 9 11 1.1 8.0 Crankshaft end cover Bolt M6 4 7 0.7 5.1 Bearing retainer (balancer shaft) Screw M6 2 7 0.7 5.1 Bearing retainer (main axle) Screw M6 2 7 0.7 5.1 Bearing retainer (left crankcase) Screw M5 2 7 0.7 5.1

Drive sprocket Nut M20 1 90 9.0 65

Stopper lever Bolt M6 1 10 1.0 7.2 Reverse shift cam stopper bolt Bolt M14 1 18 1.8 13 Drive select lever assembly Bolt M8 2 20 2.0 14 Drive select lever shift rod and

reverse shift cam Shift rod (shift pedal) locknut Nut M6 2 8 0.8 5.8

Bolt M6 1 16 1.6 11

Thread

size

Q’ty

Tightening torque

Nm m · kg ft · lb

Remarks

Use a lock washer.

– 6 –

MAINTENANCE SPECIFICATIONS

CHASSIS

Model YFM350S

Steering system

Lock-to-lock angle

Left 42.5° Right 42.5°

Front suspension

Shock absorber stroke 90.0 mm (3.54 in) Shock absorber spring free length 232.5 mm (9.15 in) Spring rate (K1) 32.00 N/mm (3.26 kg/mm, 182.72 lb/in)

(K2) 45.00 N/mm (4.59 kg/mm, 256.95 lb/in)

Spring stroke (K1) 0 ~ 45.0 mm (0 ~ 1.77 in)

(K2) 45.0 ~ 90.0 mm (1.77 ~ 3.54 in)

Optional spring No

Rear suspension

Shock absorber stroke 88.0 mm (3.46 in) Shock absorber spring free length 238.5 mm (9.39 in) Spring rate (K1) 57.00 N/mm (5.81 kg/mm, 325.46 lb/in) Stroke 0 ~ 88.0 mm (0 ~ 3.46 in) Enclosed gas pressure (standard) 1,500 kPa (15.0 kg/cm

(Min) 1,450 kPa (14.5 kg/cm (Max) 1,550 kPa (15.5 kg/cm

Wheel

Front wheel type Panel wheel Rear wheel type Panel wheel Front rim size/material 10 × 5.5 AT/Aluminum Rear rim size/material 9 × 8.5 AT/Aluminum Rim runout limit

Vertical <2.0 mm (0.08 in)> Lateral <2.0 mm (0.08 in)>

Front disc brake

Type Dual disc brake Disc outside diameter × thickness 161.0 × 3.5 mm (6.34 × 0.14 in) <Limit> <3.0 mm (0.12 in)> Pad thickness 4.2 mm (0.17 in) <Limit> <1.0 mm (0.04 in)>

Rear disc brake

Type Single disc brake Disc outside diameter × thickness 200.0 × 3.6 mm (7.87 × 0.14 in) <Limit> <3.1 mm (0.12 in)> Pad thickness 4.5 mm (0.18 in) <Limit> <1.0 mm (0.04 in)>

SPEC

, 213.3 psi)

, 206.2 psi)

, 220.4 psi)

– 7 –

MAINTENANCE SPECIFICATIONS

Model YFM350S

Brake lever and brake pedal

Brake lever free play 0 mm (0 in) Brake pedal position 50.2 mm (1.98 in)

From the top of the frame to the top of the brake

pedal Throttle lever free play 2 ~ 4 mm (0.08 ~ 0.16 in)

Drive chain

Type/manufacturer DID520V/DAIDO Number of links 97 + 1 links Chain free play 25.0 ~ 35.0 mm (0.98 ~ 1.38 in)

Tightening torques

SPEC

Part to be tightened Thread size

Tightening torque

Nm m · kg ft · lb

Engine and frame M10 73 7.3 53 Front shock absorber and frame M10 48 4.8 35 Front shock absorber and lower arm M10 48 4.8 35 Steering knuckle and front wheel hub M14 70 7.0 50 Steering shaft and frame M10 35 3.5 25 Tie-rod locknut M10 15 1.5 11 Disc cover (inner) M6 7 0.7 5.1 Front brake master cylinder M6 7 0.7 5.1 Clutch and parking brake lever assembly M5 4 0.4 2.9 Front brake hose and upper front arm M6 7 0.7 5.1 Front brake pipe and brake pipe joint M10 19 1.9 13 Brake pipe joint and frame M6 10 1.0 7.2 Brake caliper bleed screw M8 6 0.6 4.3 Rear brake hose union bolt M10 28 2.8 20 Parking brake adjusting bolt and locknut M8 16 1.6 11 Rear brake light switch bracket and frame M6 7 0.7 5.1 Rear brake master cylinder and frame M8 23 2.3 17 Rear brake fluid reservoir and frame M6 7 0.7 5.1 Rear brake hose and swingarm M6 7 0.7 5.1 Rear hub and rear brake caliper M8 34 3.4 24 Rear axle ring nut M33 160 16.0 115 Rear axle ring nut set bolt M6 7 0.7 5.1 Rear hub and swingarm (lower) M10 73 7.3 53 Rear shock absorber and frame M12 80 8.0 58 Relay arm and swingarm M12 73 7.3 53 Rear shock absorber and relay arm M12 73 7.3 53 Connecting rod and relay arm M12 73 7.3 53 Connecting rod and frame M12 73 7.3 53 Spring preload adjusting locknut (rear shock

absorber)

M44 42 4.2 30

Remarks

– 8 –

MAINTENANCE SPECIFICATIONS

SPEC

Part to be tightened Thread size

Swingarm guard and swingarm M8 16 1.6 11 Driven chain sprocket and boss M10 55 5.5 40 Front bumper M8 12 1.2 8.7 Rear bumper M8 34 3.4 24 Drive chain guard M8 12 1.2 8.7 Foot protectors (left and right) and frame M8 16 1.6 11 Foot protectors (left and right), rear fender stay

and frame Foot protectors (left and right) and footrest M8 17 1.7 12 Footrest and frame M10 73 7.3 53 Battery holder M6 10 1.0 7.2 Front fender and front fender bracket M6 7 0.7 5.1 Front fender and frame M6 7 0.7 5.1 Front fender bracket (center) and frame M6 10 1.0 7.2 Front fender brackets (left and right) and frame M6 13 1.3 9.4 Headlight bracket and front fender bracket M6 7 0.7 5.1 Rear fender and frame M6 10 1.0 7.2 Rear fender and rear bumper M6 7 0.7 5.1 Rear fender and rear fender stay M6 7 0.7 5.1 Rear fender stay and frame M6 7 0.7 5.1 Rear fender stay and frame M8 16 1.6 11 Engine skid plate and frame M8 12 1.2 8.7 Fuel tank M6 7 0.7 5.1 Fuel cock and fuel tank M6 4 0.4 2.9 Rectifier/regulator M6 7 0.7 5.1 Tail/brake light bracket and rear fender M6 4 0.4 2.9

M8 17 1.7 12

Tightening torque

Nm m · kg ft · lb

Remarks

– 9 –

MAINTENANCE SPECIFICATIONS

ELECTRICAL

Model YFM350S

C.D.I.

Magneto model/manufacturer F4T466/MITSUBISHI Pickup coil resistance 459 ~ 561 Ω at 20 °C (68 °F)

(Color) (White/Red-White/Green)

Rotor rotation direction detection coil resistance

(Color) (Red-White/Blue)

C.D.I. unit-model/manufacturer F8T40374/MITSUBISHI

Rectifier/regulator

Regulator type Semi conductor-short circuit Model/manufacturer SH640E-11/SHINDENGEN No-load regulated voltage 14.1 ~ 14.9 V Rectifier capacity 14 A Withstand voltage 200 V

Starter relay

Model/manufacturer 2768095-A/JIDECO Amperage rating 180 A Coil winding resistance 4.18 ~ 4.62 Ω

Battery

Specific gravity 1.310 at 20 °C (68 °F)

Starter motor

Model/manufacturer DBQD5/DENSO Output 0.7 kW Armature coil resistance 0.0118 ~ 0.0133 Ω at 20 °C (68 °F) Brush overall length 12 mm (0.47 in)

Brush spring pressure 6.38 ~ 9.32 N (651 ~ 950 gf, 22.96 ~ 33.55 oz) Commutator diameter 28 mm (1.10 in)

Mica undercut 0.6 mm (0.024 in)

0.083 ~ 0.101 Ω at 20 °C (68 °F)

8.5 mm (0.33 in)

27 mm (1.06 in)

SPEC

– 10 –

CABLE ROUTING

1 Clutch switch lead 2 Starter cable 3 Clutch cable 4 Parking brake cable 5 Front brake hose 6 Front brake light switch lead 7 Throttle cable 8 Neutral indicator light 9 Reverse indicator light

CABLE ROUTING

0 Handlebar switch lead

È Fasten the front brake light switch lead with two

plastic bands.

É Fasten the starter cable, clutch switch lead, and

handlebar switch lead with a plastic band.

Ê Fasten the clutch switch lead and handlebar

switch lead with a plastic band.

SPEC

ÉÊ

– 11 –

CABLE ROUTING

SPEC

1 Parking brake cable 2 Clutch cable 3 Starter cable 4 Clutch switch lead 5 Handlebar switch lead 6 Neutral/reverse indicator light lead 7 Rectifier/regulator 8 Front brake light switch lead 9 Front brake hose 0 Throttle cable

È Pass the clutch switch lead, handlebar switch

lead, neutral/reverse indicator light lead, front brake light switch lead, and starter cable through the guide.

É Fasten the clutch switch lead, handlebar switch

lead, neutral/reverse indicator light lead, and front brake light switch lead securely with a plastic locking tie.

È É Ê

– 12 –

Ê Route the clutch switch lead, handlebar switch

lead, neutral/reverse indicator light lead, and front brake light switch lead in front of the guide.

Ë Pass the throttle cable, clutch cable, and parking

brake cable to the right side of the steering shaft.

CABLE ROUTING

SPEC

È É Ê

– 13 –

+ 48 hidden pages