It is not neccessarily a long time. Alot of factors involved. Sounds like a really small butt. I am not sure it is a whole pork butt, maybe boneless. There is a point at which the meat temp will slow down, maybe stop rising, even go down some. It is called the plateau. Remember, it is done when it is done, to whatever temp you decide. 195* is great for pork butt, but you might like 185* or 205* better. Your therm probe lcd should read 32* in ice water and 212* in boiling water. Test it. then test your smoker by turning up full blast when empty and dangle the probe down the smoke hole on top without it touching anything. Write down the temp every 15 minutes after an hour warmup. It should average 250*. If you get 245* or more, count yourself lucky. If you get less than that, call CookShack customer service.
Did I miss anything?