This is very strange. Plane, 4*40 with a Magnum .52 4 stroke. Radio gear Futaba 4EXA with standard 3004 servos and reciever. R168DF


A couple of times after starting the engine and picking it up to head out to the runway, the throttle will go wide open. It mainly does this if I hold the nose of the plane up. Radio in my left hand and plane in the right hand. And its the throttle servo opening, not some sort of lean condition. It will only do this while the engine is running and NEVER on the pit table. It happened once in the air when the plane was very close and today it happened just before take off ending the day with a broken spinner where it met a concrete ledge.

There are no other glitches and the range check is fine, in fact, it wont do it when the plane and radio are pretty far apart, but if Im holding the nose up with the engine running and get the radio close, itll rev wide open allmost every time.

My thoughts are that I might be getting some sort of antennea refraction. I had this problem once with a CB antennea mounted too close to a TV antennea. When I keyed up it would open my neighbors garage door. LOL

Since I cant duplicate the glitch on the bench, I figured I would ask yall before I just try re-wiring everything.

Thanks in advance.