Main Motorcycle: '03 T-100 & '08Tiger1050
Join Date: Aug 2004
Location: Stroud, OKlahoma, USA
I remain a "doubter" on this one. All of your description except the part of definitely hearing and feeling it through the carbs is a description of a loud bang through the exhaust on warm startup--not that unusual, especially if giving a bit of throttle.
A backfire occurs only when ignition occurs with the intake valve open, partially open, or burned enough to leak. Fuel mixture should have nothing to do with a backfire, IMHO. Most people incorrectly call any popping sound from a motor a backfire. If you are certain that the "bang" is back through the carb, I would suggest a compression check and a valve clearance check. Also, as rich as many run the pilot circuitry of these carbs a fire is very likely on a backfire. If I had backfiring on my motor and the valves checked good, I would be purchasing another igniter.
2003 T-100 (790cc), NARK, NH Togas, 8100 rpm rev limiter, 158 main jets, 42 pilot jets (less than 1 turn out on pilot screws), stock needles--no shims. 13 A/F ratio from 1100 rpm to 4000 rpm; 12 A/F ratio from 4000 rpm to 6000 rpm; 13 A/F from 6000 rpm to 8100 rpm.:D
2007 Tiger 1050--White:D--SW-Motech crashbars, Skidmarx rear hugger/chain guard, Calsci +7 windscreen.