i had a thunder tiger .91 with a pipe on mine. it flew nice but did not seem to fly the way i thought a jet should. i figured out how to put my .81 rossi ducted fan motor with the pipe on it and now it flys realllllly fast. this engine comes with an onboard needle valve and fine tuning is a snap. it uses more gas than the tiger so the flight ended prematurely and i had a crash landing in the corn field. while repairs were in progress (just a little balsa on the leading edge of the right wing) i bent some 5/32 piano wire to see if i could reinforce the landing gear. can't wait to get back to the field.