RE: DL-50 engine
Switch,
It looks as though your plug wire is rubbing on the bottom of you cowl, you will want to tie that up or remove some more of your cowl or it will rub a hole thru your plug wire. I had the same issue once. The air and vibration from the engine will make this happen very quickly, you add to that the sand paper feel of fiberglass.
Just my .02.