94XP only runs with huge spark plug gap

[Neilp1286]

I have a 657x freshly rebuilt, and it only runs with a huge spark plug gap. I mean huge! Anything under .070 and it just cranks non stop. Fires right up on the first try once you open up the gap. What on earth would cause that?

I have tried 2 sets of plugs, Ngk Br8es with the same results.