Service manual
Table Of Contents
- Inroduction
- Yamaha Motor Corporation, USA YZ/WR Motorcycle Limited Warranty
- How to use this Manual
- Index
- Contents
- Chapter 1 General Information
- Chapter 2 Specifications
- Chapter 3 Regular Inspection and Adjustments
- Chapter 4 Engine
- Seat, Fuel Tank and Side Covers
- Exhaust Pipe and Silencer
- Radiator
- Carburetor and Reed Valve
- Cylinder Head, Cylinder and Piston
- Clutch and Primary Driven Gear
- Kick Axle, Shift Shaft and Primary Drive Gear
- YPVS Govenor
- Water Pump
- CDI Magneto
- Engine Removal
- Crankcase and Crankshaft
- Transmission, Shift Cam and Shift Fork
- Chapter 5 Chassis
- Chapter 6 Electrical
- Chapter 7 Tuning
4-25
ENG
CYLINDER HEAD, CYLINDER AND PISTON
EC474831
Power valve
1. Inspect:
9
Power valve 1,2 1
Wear/Damage → Replace.
Carbon deposits →Remove.
9
Valve holder 2
9
Link lever 3
9
Valve shaft 4
9
Collar 5
Wear/Damage → Replace.
9
Spring 6
Broken → Replace.
EC474901
Power valve hole on cylinder
1. Remove:
9
Carbon deposits
From power valve hole surface a.
NOTE:
Do not use a sharp instrument. Avoid scratching
the aluminum.
EC475000
ASSEMBLY AND INSTALLATION
EC4751A1
Power valve
1. Install:
9
Power valve 1 1
9
Power valve 2 2
9
Bolt (power valve) 3
NOTE:
Install the power valve at cut-away faced a for
down side.
8 Nm (0.8 m•kg, 5.8 ft•lb)
1C3-28199-10 114 04.5.17, 9:22:21 PM