Originally Posted by El Ropo
As far as why your fire is dying down. Not nearly enough info provided to help us help you.
Well, we know he started a dry cook with 15-20 lit briquettes on a light load of charcoal. I guess the only other things we need to know are A) How long was the cooker up to temp before the meat went on, B) what were the positions of the vents when the temps were down ,C) how long did he wait to see if the temp would recover and D) what conditions was he cooking in (temp, wind, etc...).
Btw, If I put 3 racks of ribs (babybacks or spares trimmed St Louis style) in a WSM that was stabilized at temp, I would expect to see a 15 degree drop in temp +/- 5 degrees.