1987-1993 Yamaha YSR50 YSR 50 Service Manual Repair Manuals, Ultimate Workshop Manual

@YAM AHA

YS R5OT SERVICE MANUAL 01987 by Yamaha Motor Corporation, U.S.A. 1st Edition, March 1987 All rights reserved. Any reprinting or unauthorized use without the written permission of Yamaha Motor Corporation, 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 their qualified mechanics. It is not possible to put an entire mechanic's education into one manual, so it is assumed that persons using this book to perform maintenance and repairs on Yamaha motor- 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. TECHNICAL PU BLlCATlONS SERVICE DIVISION MOTORCYCLE OPERATIONS YAMAHA MOTOR CO., LTD. HOW TO USE THIS MANUAL PARTICULARLY IMPORTANT INFORMATION This material is distinguished by the following notation. NOTE: 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. MANUAL FORMAT 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.

I ENG 1 ILLUSTRATED SYMBOLS (Refer to the illustration) Illustrated symbols @ to @ are designed as 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 Illustrated symbols 0 to @ in the exploded diagram 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@)

INDEX GENERAL INFORMATION m GEN INFO SPECIFICATIONS P f @ ENGINE OVERHAUL +o, PERIODIC INSPECTION AND ADJUSTMENT CHASSIS &O em INSP ADJ ELECTRICAL El ELEC TROUBLESHOOTING 0

CONTENTS CHAPTER 1 . GENERAL INFORMATION MOTORCYCLE IDENTIFICATION ................................... 1.1 VEHICLE IDENTIFICATION NUMBER .............................. 1.1 ENGINE SERIAL NUMBER ....................................... 1.1 IMPORTANT INFORMATION ...................................... 1.2 PREPARATION FOR REMOVAL AND DISASSEMBLY .............. 1.2 ALL REPLACEMENT PARTS ..................................... 1.3 GASKETS, OIL SEALS. AND O.RINGS ........................... 1.3 LOCK WASHERSIPLATE AND COTTER PINS .................... 1.3 BEARINGS AND OIL SEALS ..................................... 1.3 ClRCLlPS ....................................................... 1-4 SPECIAL TOOLS .................................................. 1-4 FOR TUNE UP .................................................. 1-4 FOR ENGINE SERVICE .......................................... 1.5 FOR CHASSIS SERVICE ......................................... 1.6 FOR ELECTRICAL COMPONENTS ................................ 1.7 CHAPTER 2 . SPECIFICATIONS GENERAL SPECIFICATIONS ....................................... 2.1 MAINTENANCE SPECIFICATIONS ................................. 2.4 ENGINE ........................................................ 2-4 CHASSIS ....................................................... 2-8 ELECTRICAL ................................................... 2.11 GENERAL TORQUE SPECIFICATIONS ............................ 2.14 DEFINITION OF UNITS ........................................... 2.14 tNtiINt ....................................................... 2-15 CHASSIS ...................................................... 2-15 CABLE ROUTING ................................................ 2.16

-- - CHAPTER 3 . PERIODIC INSPECTION AND ADJUSTMENT INTRODUCTION ................................................... 3-1 ............ PERIODIC MAINTENANCE/LUBRlCATlON INTERVALS 3.1 COWLINGS REMOVAL AND INSTALLATION ...................... 3.3 COWLINGS ..................................................... 3-3 SIDE COVER ................................................... 3.4 ENGINE ........................................................... 3.4 IDLE SPEED ADJUSTMENT ..................................... 3.4 THROTTLE CABLE FREE PLAY ADJUSTMENT .................... 3.5 AUTOLUBE PUMP CABLE ADJUSTMENT ........................ 3.5 AUTOLUBE PUMP STROKE ADJUSTMENT ....................... 3.6 AUTOLUBE PUMP AIR BLEEDING ................................ 3.8 SPARK PLUG INSPECTION ...................................... 3.9 IGNITION TIMING CHECK ...................................... 3.10 ENGINE OIL LEVEL CHECK ..................................... 3.10 TRANSMISSION OIL LEVEL INSPECTION ........................ 3.11 TRANSMISSION OIL REPLACEMENT ............................ 3.12 CLUTCH ADJUSTMENT ........................................ 3.13 AIR FILTER CLEANING .......................................... 3.14 CARBURETOR JOINT INSPECTOIN .............................. 3.16 FUEL LINE INSPECTION ........................................ 3.17 Y.E.I.S. HOSE INSPECTION .................................... 3.17 EXHAUST SYSTEM INSPECTION ............................... 3.17 CHASSIS ........................................................ 3-17 FRONT BRAKE ADJUSTMENT .................................. 3.17 REAR BRAKE ADJUSTMENT ................................... 3.18 BRAKE FLUID INSPECTION .................................... 3.18 BRAKE PAD INSPECTION ...................................... 3.19 BRAKE SHOE INSPECTION ..................................... 3.19 BRAKE LIGHT SWITCH ADJUSTMENT .......................... 3.19 BRAKE HOSE INSPECTION ..................................... 3.19 DRIVE CHAIN SLACK ADJUSTMENT ........................... 3.20 DRIVE CHAIN LUBRICATION ................................... 3.21 STEERING HEAD ADJUSTMENT ................................ 3.21 TIRE INSPECTION ............................................. 3.23 WHEEL INSPECTION ........................................... 3.24 CABLE INSPECTION AND LUBRICATION ........................ 3.24 LEVER AND PEDAL LUBRICATION ............................. 3.25 SIDESTAND LUBRICATION ..................................... 3.25 INFO

ELECTRICAL ..................................................... 3-26 BATTERY INSPECTION ......................................... 3.26 FUSE INSPECTION ............................................. 3.28 HEADLIGHT BEAM ADJUSTMENT .............................. 3.29 HEADLIGHT REPLACEMENT .................................... 3.29 CHAPTER 4 . ENGINE OVERHAUL ENGINE REMOVAL ................................................ 4-1 TRANSMISSION OIL ............................................ 4-1 COWLING AND SIDE COVER .................................... 4-1 FUEL TANK .................................................... 4-1 MUFFLER ...................................................... 4-2 CARBURETOR .................................................. 4-2 AUTOLUBE PUMP CABLE AND HOSE ........................... 4.2 LEADS ......................................................... 4-3 CLUTCH CABLE ................................................ 4.3 DRIVE CHAIN .................................................. 4-3 ENGINE REMOVAL .............................................. 4.4 ENGINE DISASSEMBLY ........................................... 4.5 CYLINDER HEAD. CYLINDER AND PISTON ...................... 4.5 CLUTCH AND PRIMARY DRIVE GEAR ........................... 4.6 KICK AXLE ..................................................... 4-8 SHIFT SHAFT .................................................. 4-9 CDI MAGNETO ................................................. 4-9 CRANKCASE .................................................. 4-10 TRANSMISSION. SHIFTER AND CRANKSHAFT .................. 4.11 INSPECTION AND REPAIR ....................................... 4.13 .............................................. CYLINDER HEAD 4-13 ....................................... CYLINDER AND PISTON 4.13 ................................................ PISTON RINGS 4-15 PISTON PIN AND BEARING .................................... 4.16 rl I IT~U 4-17 ... w. . w.. .... L. ................................................... " SHIFT SHAFT ................................................. 4-19 TRANSMISSION AND SHIFTER ................................. 4-20 CRANKSHAFT ................................................. 4-21 CRANKCASE .................................................. 4-22 AUTOLUBE PUMP ............................................. 4-22 ENGINE ASSEMBLY AND ADJUSTMENT ........................ 4.24 CRANKSHAFT. SHIFTER AND TRANSMISSION .................. 4.24 CRANKCASE .................................................. 4-25 CDI MAGNETO ................................................ 4-30 SHIFT SHAFT ................................................. 4-32

KICK AXLE .................................................... 4-32 CLUTCH AND PRIMARY DRIVE GEAR .......................... 4.34 CYLINDER HEAD. CYLINDER AND PISTON ..................... 4.37 REMOUNTING ENGINE ......................................... 4.40 CHAPTER 5 . CARBURETION CARBURETOR ................................................... -5-1 REMOVAL ...................................................... 5-2 DISASSEMBLY ................................................. 5-2 INSPECTION .................................................... 5.4 ..................................................... ASSEMBLY 5-5 INSTALLATION ................................................. 5.6 ADJUSTMENT .................................................. 5-7 REED VALVE ..................................................... 5-8 REMOVAL ...................................................... 5-8 INSPECTION .................................................... 5-8 INSTALLATION ................................................. 5.9 CHAPTER 6 . CHASSIS .................................................... FRONT WHEEL 6-1 ...................................................... REMOVAL 6-2 .................................................... INSPECTION 6-2 INSTALLATION ................................................. 6-4 REAR WHEEL ..................................................... 6-5 ...................................................... REMOVAL 6.6 .................................................... INSPECTION 6.6 ................................................. INSTALLATION 6.8 ................................................... FRONT BRAKE 6.10 ................................... BRAKE PAD REPLACEMENT 6.11 ....................................... CALIPER DISASSEMBLY 6.13 ............................ MASTER CYLINDER DISASSEMBLY 6.14 ...................................... INSPECTION AND REPAIR 6.15 ASSEMBLY .................................................... 6-16 ................................................ AIR BLEEDING 6-19 .................................................... FRONT FORK 6.20 ..................................................... REMOVAL 6.21 ................................................ DISASSEMBLY 6.21 ................................................... INSPECTION 6.23 .................................................... ASSEMBLY 6.23 ................................................ INSTALLATION 6-26

STEERING HEAD AND HANDLEBAR ............................. 6.27 REMOVAL ..................................................... 6-28 INSPECTION ................................................... 6-29 l NSTALLATION ................................................ 6.30 REAR SHOCK ABSORBER AND SWINGARM .................... 6.33 REMOVAL ..................................................... 6-34 DISASSEMBLY ................................................ 6-35 INSPECTION ................................................... 6-35 ASSEMBLY .................................................... 6-36 INSTALLATION ............................................... -6-36 DRIVE CHAIN AND SPROCKETS ................................. 6.38 REMOVAL ..................................................... 6-38 INSPECTION ................................................... 6.38 INSTALLATION ................................................ 6.39 CHAPTER 7 . ELECTRICAL YSR50T CIRCUIT DIAGRAM ....................................... 7-1 COLOR CODE .................................................. 7-2 ELECTRICAL COMPONENTS ...................................... 7.3 IGNITION AND STARTING SYSTEM ............................... 7-4 IGNITION CONTROL CIRCUIT OPERATION ....................... 7.6 TROUBLESHOOTING ............................................ 7.7 CHARGING SYSTEM ............................................. 7.16 TROUBLESHOOTING ........................................... 7.18 ............................................... LIGHTING SYSTEM 7.22 ........................................ TROUBLESHOOTING (1) 7.24 ........................................ TROUBLESHOOTING (2) 7.27 SIGNAL SYSTEM ................................................. 7.30 TROUBLESHOOTING ........................................... 7.32 DISPLAY SYSTEM ................................................ 7.42 TROUBLESHOOTING (1 ) ........................................ 7.44 TROUBLESHOOTING (2) ........................................ 7.48 DISPLAY SYSTEM TEST AND CHECK ........................... 7.50 CHAPTER 8 . TROUBLESHOOTING STARTING FAILUREIHARD STARTING ............................ 8.1 FUEL SYSTEM ................................................. 8.1 ELECTRICAL SYSTEM ........................................... 8.2 COMPRESSION SYSTEM ........................................ 8.3

1987-1993 Yamaha YSR50 YSR 50 Service Manual Repair Manuals, Ultimate Workshop Manual

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