Motorcycle Repair: rd250 yamaha, fuel air mixture, main bearings

Question
i removed the oill injection from my 74 rd250 and was wondering what i should mix the fuel oil ratio? i can't seem to find anyone who knows but they make a cover plate just for removing the oil pump so i know someone has to have the same ? out there. looking for some input. thanks josh

Answer
Josh, in some cases, removing the oil pump will damage the engine as some of the oil feeds the crankshaft main bearings. It really isn't a good idea, from what I have heard.

What's done is done, though....  If you look at the label of the 2 stroke oil, it will tell you suggested ratios. If you use synthetic 2-stroke oil, you can run much less oil to fuel than if you are using standard petroleum oils.

http://www.dansmc.com/pre_mix_ratios.pdf

http://www.dansmc.com/2stroke_oil.htm

https://www.amsoil.com/StoreFront/ait.aspx

http://www.redlineoil-europe.com/motoroil/index.asp?section=Two-Stroke+Racing+Oi...

Understand that when you go to premix, the carburetor jetting will be affected, as oil/fuel is thicker than gasoline, so moves slower through the jets, leaning out the fuel/air mixture... which can cause piston seizures.

Good luck!

Bill Silver