I have been flying for some years & have just bought my first gas engine, a 26cc with cdi electronic ignition. I fitted it to a CMpro large Mustang. My radio is 2.4 Spectrum.
I was getting severe interference when the engine was running, with all servos randomly jumping about. I tried moving the ignition control unit to various locations with no result. I burned out three servos as a result of the violent reactions. I have found that grounding the wire cased spark plug lead to the engine stops the interference. I have temporarily cable tied it to one of the engine stand off legs.
My question is, is it normal to have to do this & if so, should I make a more permanent ground, such as soldering a wire from the plug wire sheath & bolting it to the engine.