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
4-23
ENG
CYLINDER HEAD, CYLINDER AND PISTON
EC474502
Piston ring
1. Install:
9
Piston ring
Into the cylinder.
Push the ring with the piston crown.
2. Measure:
9
End gap
Use a thickness gauge 1.
Out of limit → Replace.
3. Measure:
9
Side clearance
Use a thickness gauge 1.
Out of limit → Replace piston and/or ring.
NOTE:
Check at several points.
EC474602
Piston clearance
1. Calculate:
9
Piston clearance
Out of limit → Replace piston, and piston
ring and/or cylinder.
Refer to “Cylinder” and “Piston”.
Ring end gap (installed):
Standard <Limit>
0.5~0.7 mm 1.2mm
(0.020~0.028 in) (0.047 in)
Side clearance:
Standard <Limit>
0.035~0.070 mm 0.1mm
(0.0014~0.0028 in) (0.004 in)
PISTON
CLEARANCE
CYLINDER
BORE
PISTON
DIAMETER
=
–
1C3-28199-10 112 04.5.17, 9:22:16 PM