OK, a newbie here and trying out the egg. Practice run only before do a brisket. Lit 3 places with MAPP gas, but even with vent closed, daisy wheel slide clsoed and daisy wheel vents closed (eveything closed) cannot get it to go below 280-300. Recalibrated thermometer also. Is this because no brisket in there to absorb heat? Man, this thing is really sensitive. How do you cool it dow?