Originally Posted by stultznasty
4x3/4"... Same as the exhausts... I was considering plugging one or more of the exhausts if I had too much trouble maintaining temperature but I haven't done enough long burns to determine if thats going to be an issue for me.
This is EXACTLY what the problem is. I have a 2" probe thermometer above my top grate and a 12" thermometer just below the bottom grate. They consistently read exactly 75* apart... so whatever you are reading on that small probe, add 75*ish to it and that's probably what you're getting.
Also, try bringing your UDS up to temp and then closing off 2 or 3 of the bottom vents. In my UDS, I leave my three 1"bottom intakes open and when I hit 250, I close 2 of them, and leave the 3rd open. Doing this, I can maintain 250-260 for about 16-18 hours on 16lbs of Kingsford.
I didn't get all the way through your post because I'm lazy... you are using the Minion Method, right?