Ordering new reeds from Jerry and some more jets for my carb should have it back together and running in the garage at least by next weekend if Jerry has the 88+ small v2 reeds available.

I'm assuming because the engine was loose in the chassis and moving a lot more then it should've been it was a grounding thing that caused the backfire. It never backfired the entire two days of its maiden voyage and I ran it hard as hell for a 9 hour ride one day and a 5 hour ride the second. Once I get the reeds and everything back together going to leak down test it and tighten everything down with loctite.