Yamaha WR250F Owner's Service Manual page 265

3. Lubricate:
• Piston
• Piston rings
• Cylinder
4. Offset:
• Piston ring end gap
a
d
a. Top ring
b. Upper oil ring rail
c. Oil ring expander
d. Lower oil ring rail
5. Install:
• Cylinder gasket
New
• Dowel pin
• Cylinder
Cylinder bolt
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
TIP
• While compressing the piston rings with one
hand, install the cylinder with the other hand.
• Pass the timing chain and timing chain guide
(exhaust side) through the timing chain cavity.
c
3
15
15
b
c
CYLINDER AND PISTON
6-34