I have 2 butts just over 4# each on the MES, after 8 hours they are only up to 180 degrees. Had the same problem last weekend, 9 hours for a 4# butt. I'm using the digital probe in one and an regular meat thermometer in the other, they read about the same. I smoked at 225 last weekend, started at 230 today, then bumped it up to 235. Shouldn't they be about done now?