MES 40" "Burping"?

That is usually cause by a flare up, chips catch fire, burn up all the oxygen, internal temp then drops sucking in oxygen and creating a back draft (aka smoke explosion). Speaking as a forty year firefighter, more of a problem in a building fire than a smoker. But still something you should avoid.
To prevent it, makes sure your top vent is open all the way and be sure you don't overload the chip tray.

:yeahthat: