Lots of variables...start temp of the meat, is your therm accurate, is the probe centered away from the bone? I think you should try moving the probe and see if there is a difference. Big butts do crazy thing, temp may rise to 150* real fast then sit there, aka Stall, for 5 or more hours. So far you are ok, relax and give it more time. Enjoy...JJ
Nick,I smoking a 11lbs bone in shoulder for my dads 60th tomorrow. Figured at 1.5 hours a lbs I'm looking about16 hours. But it seems to be cooking quick. It's been on about 3 hours with a steady temp of 230-240 only wsm and the meats already at 123. That seam too fast ???? Suggestions???