I have a 1956 David Bradley with the model 14 Briggs engine. After buying I realized the spark plug hole threads were stripped. I had an insert put in but the guy doubted it would hold so I found another head and gasket on Ebay. Same part numbers an all that. But when I received the head I noticed the spark plug hole was larger than the 14mm of the original. Anyway does anyone know what plug I need and where I can find one?
I tried one from a local small engine repair place and the threaded end is the right diameter but the reach is too long. The intake valve hits the tip of it. The one I tried was a Champion D16. Appears to be 16mm on the threaded end.