RE: gas engine interference
It is highly unlikely for twisting any wires to help. Make sure that you have not developed a loose metal to metal joint somewhere. Flying wires? Landing gear? Braces? metal clevis? etc. Also check your plug, has it carboned up? You are using a resistance plug, right?
Your antenna has not been compromised, has it, like being yanked and breaking inside the insulation (looks okay but isn't)?