I seem to have a similar problem when i down shift through the gears,usualy into 2nd or 1st at low speeds it will sometimes give a cough back through the carbs when i blip the throttle, but the engine doesn't die.I have tried every mixture screw setting there could possibly be to remove it with no luck,even changed to 45 pilots and it's still there,
Also ever since i cut the bottom of the airbox out I sometimes get a single backfire when backing off the throttle from speed and letting the compresion slow me like when entering an intersection, that was never there before the mod.
