ive got a question for the guru.i figure if anybody knows what their talking about its you guys.alot of the other forums are too many cheifs and not enough indians.i recently bought an engine from thunder tiger,the pro bx .70.rumor has it,that its an airplane engine,and in the book it said the fuel is recommended 75% methanol,25% lube,and a fuel with a nitro content of 5-30% may be used when more power is needed.ive lost the manual for it,and nobody can seem to give me any info on what this fuel is.i guess my big question is how much of an increase in power can i expect from the 30% fuel? its rated at 2.5 hp on the recommended fuel.any info you guys can give me would really help,cuz this is starting to become a wild goose chase.

Hi S.C.; As one who has been doing this since the mid-late 30s, although I didn't hit glow stuff until '45, over the years it has been my experience that for sport , non-racing use, 5-10% is generally ideal. The principal value to the sport flyer is in smoother, more reliable idle, and smoother acceleration. When you talk 30% or more, that's racing fuel, and heat becomes a problem. The basic non-nitro fuel is a good basic fuel for all around use, and usually the most economical. My personal overall choice has been 10% nitro. I don't race, but I like reliable idles and smooth acceleration, and this does it for most engines. With 4-strokes, 10-15% is recommended, as that in-between cycle likes to cool the plug somewhat, and the nitro fuel ignites a bit faster. But try fifferent fuels in the 0-5-10 range and see which your engine likes. THAT is the real proof of the pudding! Sincerely; Lee Robinson ROBINAIRE, W. Palm Beach, FL.