Well I finally got around to pick up a motor mount for the 61FX and got talking to the owner of the hobby shop in the town that I'm working in and he said that the 61FX is over kill for this plane . He said that here in WI. the sea level that we are at all I need is a 46FX with a low pitch prop and it will pull out of a hover and climb unlimited vertical. He said the 46 will fly all the 3D you can throw at it. When I told him most of the guy's posting on rc universe and Flying G's are using bigger engines He said they were probably flying at higher altitudes. If anybody tried a 46FX on this plane or if you can confirm the reason I should use the O.S.46FX instead of the O.S.61FX let me know I have both engines not being use right now