What are you using to smoke these, and what temps are you smoking them at? Low and slow is the way to cook pork butts. You have to take them to 195 degrees IT, and then start probing them with a skewer. When the probe goes in and feels like warm butter, they are done. I would kick your temp up to 250 or 275. It isn't temp and time, but the internal temp of the meat, and the feel of it when it comes out. Pork butts, and briskets should feel and wobble like Jello when it is done.