4 stoke or 2 stoke - I doubt it makes much difference. The oil that comes out the tail pipe of my OS 40 LA is nice and thick and black. In fact I beileve that that is the kind of oil that you would find in the 4 stroke because it can only get oil left over from combustion and on my mix that is nice thick oil.

I've been flying my mix a bunch the last couple of weeks. I put a 13x5 prop on this little engine and it pulled it great. I finally crashed yesterday so now I will have to dissasemble the engine to clean it.

Treven.