A buddy of mine gave me a plane that had a 46FXi...i heard they are basicly the same thing as the FX series just slightly different. well the compression is great, and ran OK, but not great... ive decided to swap out motors and old but more powerful st50... upon taking the 46 fxi out i looked in the exhaust port and its tiny, ive never seen that much sleeve showing through an exhaust port ever... is this normal>?