DDayWarbird

My Feedback: (5)

Hello, I am new to this 4 stroke engine. I have an new OS 91 and a new OS120. After complete break in and about 8 to 10 hours on the engine, I read that using 30% Heli fuel is a great thing to do. Any answeres out there, or suggestions.

Bax

My Feedback: (11)

With most four-stroke engines, you won't get much performance improvement once you go over about 15% nitro in the fuel. At high field elevations, or in colder weather, the higher nitro may help, but usually, it doesn't.