I just bought a new Evolution 46. It runs great, the only thing I had to do to start it was turn my plane upside down. (my engine is mounted upside down on the plane.) I had it on a trainer and crashed it violently into the ground. The carburater, muffler, and needle valve assembly broke, but I like it so much I'm going to buy another one. I had a tuned pipe on it for one tank of flying and the sound of the air going by the plane made more noise than the engine! For some reason, the pipe worked only on that one flight, I can't start it now unless I use the stock muffler. It runs just fine now anyway, and maybe I need a little more tuning of the engine to fit the pipe.