Thanks Steve, I am running the OS .40LA now and I am running a 10x6 prop. I have tried a 11x5 plastic prop as well. Everything I read says to run the 10x6 up to the 11x5. It does fly after take off. I can fly right at half throttle as long as the wind is not very strong. It just seems like it is working way to hard to attain lift off. What I was thinking was I could put the OS .46AX on this plane and then switch back when I build my next plane so it would be broken in. I have been flying heli's and new to the planes so not sure if that would be to much for the high wing trainer. Thank you very much for the response. Mike