the wire in the anttena may have been damaged, or disconnected at the pc board. Try range checking just thr rx or the rx in another plane. THere could also be a fracture that occurs only whern the engine is running(vibration). INsted of recovering if you want to be safe, buy a deans, etc, whip antenna. They're about 10 bucks and when mounted to the. remember depending on the route of the wire, how much surface area the rx may get. ? do you see the end, a samll dot, or 39 in of wire laid out.

I have had entire airplanes covered in crome, gas engine in it to boot. Not one problem.