Well i ride a wr 426 and as the title says pops n stops on deceleration, not all the time and it doesn't matter if its snapped shut or closed gradually, occasionally when coming to rest it pops out the air box and stops. Checked/cleaned:- Carb, jets, float bowl height. Air intake rubbers. Exhaust seal, pipe Cut off switch, for shorting. Plug, gap set, plug lead cleaned. Been into my local dealer and the above was suggested. Read through the manual and i can't figure out what the problem is, need some help please. Other than that the bike runs strong and true. Can be a bit of a pain to start from hot but hopefully managed to sort that out. Think its intake:- main jet 165, main air jet 200, needle jet OBDQR clip 5, starter jet 65, Pilot jet 42, Pilot air jet 75, Fuel screw 1.5 turns out. WR timed, Sea level to around 1000' Not much elevation in southern England. Thanks in advance, cheer Rich.