My 2010 CVO UC has 50,000 miles on it, a stock engine, except for cams. Going back in my memory at least 25k to 35k miles ago (long before I put the cams in), about 1 in 10 starts, the engine violently backfires on startup, almost like a small explosion. Last week I took the outer primary off and took the SE compensator apart and the teeth on the compensator assembly that goes on the main shaft were worn out of spec with some play back & forth. So I'm thinking the backfiring caused the compensator to wear and fail, or the compensator failure caused the backfiring.
I'm replacing the compensator assembly today, so I'll find out if it still backfires, but my hunch is it will. If the backfiring continues it will destroy the compensator again so I need to address this now. Has anyone experienced this issue and if so, what could cause violent backfiring?