Hi all. I'm sure I'm doing something really obviously wrong but I can't figure it out nor can I think of what to try next. Here's my current problem: I have a new Brinkmann Trailmaster and I have performed the seasoning procedure and also have tried a couple of trial "dry" runs (i.e. without food). I read this common sense suggestion to do some dry runs to get the hang of temperature control. From all the videos I've seen on Youtube everybody seems to start out with a full "chimney" (charcoal starter) of charcoal and then later add wood. They seem to have an easy time of getting the temp up to 250 and can then seem to keep it there fairly easily. WELL when I start with a full chimney of white hot charcoal my temp gauge (I've tested it in boiling water and it seems to work) SHOOTS up between 450 and 500 in no time. It takes forever for it to get back down between 350 and 400. It takes the coals almost going out to get it down around 250 BUT THEN that lasts for like 15 minutes. If I add a chunk of wood, it ignites and the temp goes back up around 400. I'm keeping the chimney vent wide open and the air intake damper valve (on the fire box) between 1/2 and 1/4 of the way open. QUESTION: What could I be doing wrong and what should I try???? THANK YOU SO MUCH FOR YOUR HELP!!!