Loud Popping Bang During Engine Start

[09Busaa]

Would appreciate any help I can get.
Year:
2009

Background:
Parked the bike for over 6 months because I was gone.
After my return, the bike started just fine but it was time for me to transfer to another location.
The movers wouldn't let ship the bike without a current registration (from HI).
So given the time shortage, I relunctantly rode it to the DMV, then to the safety check spot then back to the DMV-approx. 25miles without being serviced first.

Rode back home and turned it off, then tried to fire it up again and it wouldn't start.
Not a battery problem-I installed a fully charge Shorai battery.

When the starter is engaged, the engine attempts to start but ends in a loud pop/bang and as long as the starter is engaged, the popping continues and the bike doesn't start.
Does anyone have any experience with this? thanks guys.

 

[Assassin8]

If the bike has been standing for a while, like you say, it is possible that one of your exhaust valves has stuck open, especially if conditions were moist. You might have to remove the exhaust and shine a torch light in the ports while someone turns over the motor for you. Look to see if all the valves are closing all the way.... If the ignition timing is out can do the same thing, but impossible for timing to go out I think....