I stopped trying to preach that some popping is normal a while ago because no one listens. Modified cars do it, modified bikes do it and all for the same reason. FI shuts off fuel the same way when the throttle is closed.
I agree that a bit of poppity-pop and crackling on decel is normal because you would have to run excessively rich to get rid of all that. Backfiring is not normal. If it goes "BLAM!!!" out the pipes you need to tune that out.
Good post. Popping in the exhaust is "backfiring" and tends to be a normal side effect of mods. Poping out of the intake is called pre-ignition or detonation and is extremely bad for the engine and should not happen under any circumstances. Severe damage can result from detonation.
I know ive seen many race cars flaming and popping out the exhaust inbetween shifts. Its a performance issue not to be confused with a bad tune or lean condition. Most desired when max fuel and performance is wanted. It wont hurt a thing..but what the hell do i know I thought my KP had 20s on it..but in my defense the lager was tasting good when i posted that thread..But I like it when my KP pops between shifts sometimes..scares the crap out of folks..I wouldnt change a thing..It runs great