There is a speed controler in it. I had one of these J-3's as my first plane. It is built into the receiver. So if you fry one... there both done. You do have the FW-190 wing set up so the dihedral is up... do you? The hop up engine will also draw more amps than the stock 370 "can" motor. I won't say that it will fry but these planes were not designed for heavy modification without swapping out all of the electronics. I do know that the FW-190 has a jumper on the receiver so that you can use a 3s Lipo instead of the NmHi battery packs though so it may be a better choice. I was wondering though. Both of these planes you are working with are 3 channel and only have 3 channel transmitters. Are you do you have the rudder and ailerons working with this set up? Or did you replace the reciever and using a 4 channel transmitter? Tell me about your set up.