Yamaha YZ125 YZ250 1985-1987 / YZ490 1985-1990 Clymer Motorcycle Repair Manual

Description

This Clymer Yamaha YZ125 YZ250 1985-1987 / YZ490 1985-1990 Repair Manual provides detailed service information, step-by-step repair instruction and maintenance specifications for 1985-1987 Yamaha YZ125, 1985-1987 Yamaha YZ250, and 1985-1990 Yamaha YZ490 motorcycles.

1985 1986 1987 1988 1989 1990

Includes everything you need to know to perform tune-up and routine maintenance on the engine, clutch and transmission, fuel and exhaust, ignition system, steering and suspension, wheels, brakes and tires, electrical system, frame and body. Features complete wiring diagrams and 272 illustrated pages.

Clymer Yamaha YZ125 YZ250 1985-1987 / YZ490 1985-1990 Repair Manual Table of Contents

QUICK REFERENCE DATA

CHAPTER ONE / GENERAL INFORMATION
Manual organization / Service hints / Torque specifications / Safety first / Special tips / Expendable supplies / Parts replacement / Serial numbers / Basic hand tools / Tune-up and troubleshooting tools / Mechanic’s tips / Safety

CHAPTER TWO / TROUBLESHOOTING
Operating requirements / Troubleshooting instruments / Emergency troubleshooting / Engine starting / Engine performance / Engine noises / Excessive vibration / Two-stroke pressure testing / Clutch / Transmission / Brakes / Water-cooling system (YZ250 and YZ125) / Front suspension and steering / Ignition system

CHAPTER THREE / LUBRICATION, MAINTENANCE AND TUNE-UP
Routine checks / Pre-checks / Tires and wheels / Lubricants / Periodic lubrication / Periodic maintenance / Tune-up / Storage

CHAPTER FOUR / ENGINE
Engine principles / Servicing engine in frame / Engine / Cylinder head / Cylinder / Piston, wrist pin and piston rings / Break-in procedure / Magneto / Reed valve assembly / Crankcase and crankshaft / Kickstarter / Service and adjustment

CHAPTER FIVE / CLUTCH AND TRANSMISSION
Clutch / Clutch cable / External shift mechanism / Primary drive gear / Drive sprocket / Transmission

CHAPTER SIX / FUEL, POWER VALVE AND EXHAUST SYSTEMS
Air cleaner / Carburetor operation / Carburetor service / Carburetor adjustments / Fuel shutoff valve / Fuel tank / Energy induction system (YZ490) / Power valve induction system / Exhaust system / Exhaust system decarbonizing / Exhaust system repair

CHAPTER SEVEN / IGNITION SYSTEM
Capacitor discharge ignition / Magneto (outer rotor) / Magneto (inner rotor) / Magneto coil testing (all models) / Capacitor discharge ignition unit / Ignition coil / Spark plug / Engine kill switch / Wiring diagrams

CHAPTER EIGHT / COOLING SYTEM
Cooling system inspection / Radiator / Water pump

CHAPTER NINE / FRONT SUSPENSION AND STEERING
Front wheel / Front hub / Wheels / Tire changing / Tire repairs / Handlebar / Steering head / Front fork

CHAPTER TEN / REAR SUSPENSION
Rear wheel / Rear hub / Driven sprocket / Drive chain / Tire changing and tire repairs / Spoke and rim replacement / Rear swing arm / Rear suspension (Decarbon Monocross System)

CHAPTER ELEVEN / BRAKES
Front disc brake / Front brake pad replacement / Front caliper / Front master cylinder / Front brake hose replacement / Front brake disc / Bleeding the system / Rear brake / Rear brake pedal assembly

CHAPTER TWELVE / SUSPENSION ADJUSTMENT
Yamaha factory accessories / Front fork / Rear shock absorber

INDEX

WIRING DIAGRAMS