This repair manual is for the Yamaha IT125-490 spanning 1976-1986. You can see the specific models covered by year below. It is 352 pages and catalog number M414.
MODELS COVERED
1980-1981 YAMAHA IT125
1977-1983 YAMAHA IT175
1984-1986 YAMAHA IT200
1977-1983 YAMAHA IT250
1976-1979 YAMAHA IT400
1980 YAMAHA IT425
1981-1982 YAMAHA IT465
1983-1984 YAMAHA IT490


QUICK REFERENCE DATA

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

CHAPTER TWO / TROUBLESHOOTING
Operating requirements / Troubleshooting instruments / Emergency troubleshooting / Engine starting / Engine performance / Engine noises / Excessive vibration / Two-stroke pressure testing / Front suspension and steering / Brake problems

CHAPTER THREE / LUBRICATION, MAINTENANCE AND TUNE-UP
Pre-checks / Tires and wheels / Lubricants / Cleaning solvent / Periodic lubrication / Periodic maintenance / Engine tune-up / Storage

CHAPTER FOUR / ENGINE
Engine principles / Engine lubrication / Engine cooling / Servicing engine in frame / Engine / Cylinder head / Cylinder / Piston, piston pin, and piston rings / Break-in procedure / Magneto / Reed valve assembly / Compression release (IT400C only) / Crankcase and crankshaft / Kickstarter / Service and adjustment

CHAPTER FIVE / CLUTCH AND TRANSMISSION
Clutch / Clutch cable / Clutch release (push lever) mechanism / External shift mechanism / Transmission and internal shift mechanism

CHAPTER SIX / FUEL AND EXHAUST SYSTEMS
Air cleaner / Carburetor operation / Carburetor service / Carburetor adjustments / Fuel shutoff valve / Fuel tank / Fuel filter / Exhaust system / Exhaust system decarbonizing / Exhaust system repair

CHAPTER SEVEN / ELECTRICAL SYSTEM
Capacitor discharge ignition / Spark plug / Magneto / Ignition coil / Engine kill switch / Lighting system / Speedometer housing / Wiring diagrams

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

CHAPTER NINE / REAR SUSPENSION
Rear wheel / Rear hub / Drive sprocket / Drive chain / Wheel balancing / Tire changing and tire repairs / Rear swing arm / Rear suspension (DeCarbon monocross system) / Rear suspension (monocross type)

CHAPTER TEN / BRAKES
Front brake / Rear brake / Front brake cable / Rear brake pedal assembly

CHAPTER ELEVEN / FRAME AND REPAINTING
Kickstand (sidestand) / Footpegs / Frame

SUPPLEMENT / 1981 AND LATER SERVICE INFORMATION

INDEX

WIRING DIAGRAMS