[size=2][font="Arial"]I'd like to know if anyone out there can tell me if the 91fx is mounted on it's side on a U can Do 60 How do I get the muffler to clear the fuselage? If I Buy a tuned pipe system or a pitts style muffler which will fit best in the cowl If either will fit at all. I'd like to keep from invering a two stroke as mine is new and according to the OS rep you need to run two gallons of fuel through a two stroke before inverting it. As it sits a 91fx muffler will not fit on this plane without leaving the cowl off completely. I think if running a two stroke inverted is difficult they should not reccommend two stroke engines for such a narrow plane especially on a plane for beginners at 3D. Sorry to be long winded but any help in resolving this is greatly appreciated