I have had a 4*60 for a couple of years now and am flying with an OS91 surpass 4 stroke. To me it has the right amount of power and is a great plane to fly. I would recommend a 91 four stroke for this plane. I had to add a lot of weight to the nose to balance, but do not go by mine. I made my pilot out of a super mario brothers bobble head doll, so it was pretty tail heavy.