ORIGINAL: jetfixr
The throttle push rod is a cable actually with a plastic guide. I have a plastic ball link on the carb and a set screw on the throttle end. No, it is not a mini servo. It is full size, but it is just a standard servo. I have everything as far back as I can get it I think. The rx battery is at least 22 inches behind the ignition module, and probably at least a foot behind the throttle servo. I don't believe I can relocate the servo any further back. I will try a new servo tomorrow and see if I get any change. Thanks for the input!
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If the cable inside of the throttle's plastic guide is metal, or other conductive material, it will act as an antenna and it will direct RF back to the receiver, whether there is a metal pushrod end or not. You need to go with a totally nonconductive throttle actuation system. Yes, sometimes folks get away with using conductive throttle linkages and sometimes they do not. Do not is more the norm.
A friend of mine who is also an electrical engineer, used to leave the return spring hooked up on his carb, a normal strong servo and a single piece of kevlar fishing line to pull the throttle open. The stock spring would return the butterfly in the carb back toidle. Should a knot come loose and the kevlar line unattach, the spring assures the engine's return to idle.
Ed Cregger