i ve got a lil 50, but mines watercooled, anyway the clutch is slipping a little bit, it wont get fullspeed rigtaway like it use to, i have to ride like 50 metres before the bike will grab, and when it does i end up on my %&#!¤, so im worried im not using good enough oil, i live in australia, so could you please give me a chart with the correct oil i should use