ooops, I already have the new head on the way. oh, well I think I will turn this into a learning experience and try it anyway. I think I can give a true account of what happens, but I will warn you that I am bias toward TT engines. Not only do I run all TT in all my planes, except for 1 Magnum 4 stroke. I just recently purchased a glow powered car with the 15 sized TT engine that I just have barely broken in. It kicks but too. I have had trouble with a 42 TT that had an air bleed arb that was mounted inverted, but other than that I have had no complaints. I may have jumped the gun on the first bit of advice I recieved, but that was based on my past experience with TT. So, here is my plane. I am going to procede with attempting to put the converted 36 in the helicopter, but I would like to test it first. The engine has been broken in, but has never been mounted before. Does any one know of a good test for a heli engine, without having to acctualy fly it in a heli. If not, I need to wait till xmas. The Hawk Sport is my wife's present to me. Well, I have been hinting at it since July and I have been a good boy.