How much oil do you need to mix with my 85cc 2 stroke Kawasaki dirt bike?

Any high performance premix oil made for motorcycles is ok. Do not, however, use premix made for weedeaters, chainsaws or outboard boat motors. Motorcycle premix oil comes as either petroleum, semi-synthetic or synthetic oil and is mixed with gas at a ratio ranging from 16:1 (petroleum) to as high as 100:1 (synthetic).