Mmmmm, thats a good idea. I have experience with common two strokes, I've never had the pleasure of a tuned pipe, but with two stroke and four stroke I have flown the same manuvers and must say that a four stroke works better for me as far as low end power and throttle response. Also, as someone has already pointed out, four strokes will swing a larger diameter prop, ensureing enough prop wash over the tail plane, allowing much greater control. Before any purchase, I research the specs of all engines in that field. Compare weight, BHP, RPM, suggested props, etc. Not all suppliers supply pertinant info on their products, but it does make the choice easier. Joe