Ok, so I'm doing my first cook on my WSM 18.5, Mr brown pork butt and I'm 2.5 hrs into it and I'm having a bit of a temp spike, I've just about shut down all bottom vents except one, it's about 15% right now. It got up around 310 on the dome but it seems to be falling back a little now. Any suggestions? Is this normal for this pit? I just got this off of CL and its never been used, looked brand new in and out, will it take a few cooks to season? I must mention, I'm not using any water in the pan, read that you don't have to, gives better bark and wastes fuel, but maybe I should? Not sure, thanks!!