Yamaha Banshee 350 Manuel Du Propriétaire page 114

cC
8 In order to prevent clutch slippage (since
the transmission 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.
8 Make sure that no foreign material enters
the crankcase.
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