Yamaha RAPTOR YFM660R Owner's Manual page 122

CAUTION:
Be sure to use motor oils that do not contain
anti-friction modifiers. Passenger car motor
oils (often labeled "Energy Conserving") con-
tain anti-friction additives which will cause
clutch and/or starter clutch slippage, resulting
in reduced component life and poor engine
performance.
Oil quantity:
Total amount:
2.3 L
With oil filter cartridge replacement:
1.95 L
Periodic oil change:
1.9 L
5-15