I have an ARF Dazzler with a Magnum .52 four-stroke. It flies great! However, sometimes I wish it had just a little more power. It doesn't quite have the oomph to do true 3-D manuevers. (Not that I have the ability!) The engine is several years old, so maybe it's just getting a little weak, but it still runs well. I get ten minute plus flight times with the stock tank.