Yamaha RS90K Service Manual page 271

a
2
3
4
È
90˚
be
45˚
10. Lubricate:
11. Install:
NOTE:
Be sure to install the piston rings so that the manu-
facturer's marks or numbers a face up.
12. Install:
1
NOTE:
• Apply engine oil onto the piston pin.
b
• Make sure that the "Y" mark a on the connecting
• Reinstall each piston into its original cylinder
13. Offset:
c
a Top ring
b 2nd ring
c Upper oil ring rail
d Oil ring expander
90˚
e Lower oil ring rail
È Exhaust side
ad
5-69
CRANKCASE
• Crankshaft pins
• Connecting rod inner surface
(with the recommended lubricant)
Recommended lubricant:
Engine oil
• Top ring 1
• 2nd ring 2
• Upper oil ring rail 3
• Oil ring expander 4
• Lower oil ring rail 5
• Piston 1
(onto the respective connecting rod 2)
• Piston pin 3
• Piston pin clip New
rod faces left when the punch mark b on the pis-
ton is pointing up. Refer to the illustration.
(numbering order starting from the left: #1 to #3).
• Piston ring end gaps
ENG
4