That's the trick to using these engines, something with a high lift wing-like a Cub. If anyone is looking for a high performace engine you won't find it here, these engines are heavy for the power they put out, they are reliable and cheap to operate,that 's where their strength lies. I'm planning to put my 31cc Ryobi(converted myself) in a 1/4 scale Sig Cub, I think it will be fine for that.---------BladeRunner.