Is SAE 30 the same oil whatever you use it for? I need some transmission oil for my moped and it states SAE 30 engine oil or GL gear oil - if I find SAE30 can I buy anything whether it's for lawnmowers/4 strokes/2 strokes/cars whatever??
I'd buy some dedicated stuff from a motorbike shop to be on the safe side. Make sure it is specifically gear oil, not sump (engine) oil as they may be formualted different and have different properties:
The original post specified it was 'transmission oil' that was needed, hence gear oil was my reccomendation. I am assuming it is a two-stroke bike with a auto / semi-auto gearbox.
If ever in doubt check the API number, this will indicate the composition of the oil better than the SAE number. Foaming agents etc all affect the behaviour of oil.
Gear oil has different properties to engine oil.
Buy the proper gearbox oil, I would recommend Silkolene or Rock oil in the appropriate weight.
Standard engine oil will go very thin very quickly as it gets smashed about by the gears.