Yamaha RAPTOR YFM660RR Owner's Manual page 292

Recommended engine oil:
See page 10-2.
Oil quantity:
Periodic oil change:
1.9 L
With oil filter cartridge replacement:
1.95 L
Total amount:
2.3 L
CAUTION:
_
G
In order to prevent clutch slippage (since
the engine oil also lubricates the clutch),
do not mix any chemical additives. Do not
use oils with a diesel specification of "CD"
or oils of a higher quality than specified. In
addition, do not use oils labeled "ENERGY
CONSERVING II" or higher.
G
Make sure that no foreign material enters
the crankcase.
_
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