Motorcycle Repair: Crank, no start on 03 Yamaha V-star 1100, yamaha v star, v star 1100 custom

Question
Hello, I have an '03 v-star 1100 custom with a P.C.S. 2 into 1 exhaust and a "Maxflo Big-air kit" I installed myself(15yr journey G.M. tech). Bike was running fine for last 3 weeks. I have just come back home to list/sell bike and it will not start. Cranks fine, has new fuel, has compression, has spark. Cranks for 10 seconds or so, then backfire through exhaust(blueish flame). Any known issues with crank or T.P. sensors(does it even have these. Thank you for any leads or avenues of thought that you can provide.

Answer
I would start by having the valves checked.  If it wasn't properly jetted when the "big air kit" was added it would cause the problem that you are talking about.  The valves have to be "in tune" for them to run properly.  To me it sounds like a valve issue.  I hope this helps.