billmcb wrote:1st pic within 2min 2nd pic after 20 min
After a lengthy burn there should be about a 2" ring of dead ash around the outside of the hot coals, and corresponding fairly closely to the outer ring on the top of the burn pot. If you have hot coals close to or going over the edge you're getting an incomplete burn. In that situation you need to increase the air setting (in small increments) so that you have the 2" ash ring after a long burn.
Also, are you pulling the cleanout lever regularly and is the cleanout cover sealing properly when closed?