Originally Posted by Ron_L
I've done turkeys on my Eggs, Weber Kettle and pellet grill and have never had an issue with the dark meat finishing before the white meat. Do you have the water pan in the WSM as a heat diffuser?
The water pan is in place but is left empty.
I smoked a pork tenderloin a few weeks ago and was surprised to see how much more cooking took place from the bottom. A cross section looked pink with a slim grey area around the edges but the bottom probably had 1/8-1/4" of grey to it. So that's what I think is happening here. The dark meat is taking a majority of the heat and is being overcooked.
I don't know how this can be stopped unless the bird is cooked breast down- which would be a pain with a probe...but then maybe the dark meat wouldn't be done. Maybe spatchcocking is the answer.