Yamaha R15 2022 Service Manual page 268

4. Offset:
• Piston ring end gaps
a. Top ring
b. 2nd ring
c. Upper oil ring rail
d. Oil ring expander
e. Lower oil ring rail
A. Exhaust side
5. Install:
• Dowel pins
• Cylinder head gasket
• Cylinder "1"
TIP
• Use the piston base "a" as shown in the illus-
tration.
• While compressing the piston rings with one
hand, install the cylinder with the other hand.
• Pass the timing chain and timing chain guide
(intake side) through the timing chain cavity.
Piston base
YSST-604
(90890-01067)
a
1
CYLINDER AND PISTON
A
New
1
5-31
ENG