A while back I was having issues with the tray going out and having to be re-lit a few times while smoking jerky. ~160°. So I read what I could find on the forums and attributed it to not having enough air-flow. I added a stack to the top outlet and put a small PC fan pushing fresh air into the unit. The last time I made jerky it didn't go out once and burned as expected.
The other night I put on a boston butt to smoke for a put-luck at work. I brought the smoker up to temperature (240°) before lighting the AMNPS. I got it lit and placed it in the smoker, monitoring the smoke plume and temperature. I checked on it about 2.5 hrs into the process and noticed it wasn't smoking so I assumed the tray went out. I opened it up and found the pellets had completely burned and were just coals at this point. I reloaded the tray thinking I had put it to close to the heating element and that caused them to burn to fast. I then moved the tray as far from the element as possible lit it again and placed it back in the smoker. I checked on it again about 2 hours later and got the same result.
Is it possible there is to much air in there now, or is it the higher smoking temperature causing it to burn a lot faster?
Also I should add that I have the chip tray and housing around element completely removed, not sure if that matters or not.