I smoked two 7 lb pork butts for the 4th.  It took over 19 hours and I only reached an internal temp of 190! I was using an 18.5 WSM with a stoker attached (first long smoke with the stoker).  The fire temp was a steady 210 for the entire smoke.  The roasts stalled at 150 to 160 for over 5 hours and then the temps rose slowly over the next 7 hours.  It has been my experience that after the stall the temps rise relatively quickly.  It ended up great but really late.  I estimated 10 to 11 hours for the smoke (90 minutes per pound of a single roast).  So my question is where did I go wrong with my time estimate?