I have a new Masterbuilt 40" - 2 door gas smoker that I just got. I'm smoking an 8 pound pork loin today. I'm having trouble getting the smoker temperature low enough. I'm trying to get it to about 220 - 225 and I can't get it below about 260. So far I've replaced the in-door thermometer that was off by about 70 degrees and checked the new one with an oven thermometer inside on one of the racks. They are both reading 260 now. I also closed off the slots in the chip pan with aluminum foil to keep flame from getting into the pan and igniting the chunks. I'm running it at the lowest setting and it's still running too hot and the top vent full open. Anybody have any tips to get the temperature down where it should be? Thanks for the help.