Maidened mine today,its powered by a Thunder Tiger 130 4 stroke that has a OS120 flex pipe. Had to have a coupler made up to suit the thread at the exhaust end.Flys great ,I'm running a 16x8 to break it in and will go to a 17x6,and then maybe a 18x8 later on.I added my own registration on the fuse and under the wing.Got 2 flights in today and it was flying so nice I decided to do some low and slow passes...I still have some idle issues but once shes broken in it'll be fine.These bipes fly nice don't they..