i can not get this girl above 150 celcius. the fire box top gets to 270 c. i have enlarged the fire box to cook chamber opening and think now i have ask going into the chamber. the opening at the rf plates is as big as fire box hole, yet i am wondering if i dont have enough draw out the exhaust even though it is 4 inch. i can take the stainless extension out but it makes little difference. any one help me out, cheers.