I have a single door Masterbuilt propane smoker. The last 3 times I have smoked something, it has taken much longer than what I had calculated for the meat to get done. I know occasionally it can take longer, but every time? I have a 9 lb butt in there now that I put on at 1AM and it is still going. Is there something I am doing wrong? Do I need to modify the smoker to keep insulate it better? Any recommendations will be greatly appreciated. I am just getting tired of telling people it will be ready at a certain time and then everyone having to wait. Luckily I got smart this time and started last night. This is about the 6th time I have ever smoked anything so I am still new to it.