I recently purchased a Patty Wagstaff Extra 300 with a Turnigy 50HP engine. When running the engine at idle or slightly above, both elevators go full up deflection and flutter. However, as the throttle is advanced the elevators act normally. No other servos are affected, just the two elevator servos. I changed everything, i.e., new Spektrum 2.4 receiver, new switches, wiring, batteries, servo reverser harness, etc.. A radio range check without the engine running was good to over 120+ feet without a flutter or loss of control. However, with the engine running the elevators again fluttered and went to full up deflection just standing next to the airplane. I put two new servos on the elevator, but had the same result. The Turnigy is my first experience with an ignition engine and know little about what happens when an ignition module starts to go bad, e.g., does it cause interference and would it be localized to only one radio function such as the elevator? This engine has the original blue ignition system and I read that they have a bad reputation for failure. So if the ignition is my problem, what should I replace it with?
Any suggestion would be much appreciated.