1992 Trail Boss 250 2 stroke

[James Roscoe]

What is the best fuel mix ratio to use in a 250. I have deleted the oil injector. I have seen anything from 50:1 to 32:1. Figured someone here would have had experience and know the best ratio.

[fbiondip]

Estimated Friend old two strokes manufacturers used to recommend 25:1 even 20:1 fuel to oil ratios but that was when 2T oils were in their early development phase and there were no EPA regulations..nowadays oil manufacturers recommend 50:1 f/o ratios. That is 2% oil in volume (in other words 2 liters of oil for every 100 lts gas).Depending on the oil manufacturer ,there some that even recommend lower f-o ratios like 1.75% .it all depends on what kind of use you intend for your machine  and the smoke ammount you (or your neighboors) are willing to accept .On the safe side if your bike is air cooled a 50:1 (0r 2%) ratio should be fine with no issues whatsoever for a healthy  and prolonged engine  life , then see if smoke is acceptable for your taste, if too much you can lower it down to 1.75% provided you use ONLY high quality API-TC oil suited for your engine, whether is air cooled or water cooled . Synthetic oils are best but pricier, if you can afford the cost you can't go wrong with them,Good luck with your choice!