burn pot fire not full circle

What is the allowable tolerance of warp to the fines plate measure
Thanks again,
Sperry

Fire was started last Saturday. 4 feed 5 air setting. Pic was taken when I turned the aqua-stat up from 160 to 180 and ran the domestic hot water to cool down the boiler to 150 just prior to the change. I'll give more air a try, that has been average fire diameter.
Thanks,
Sperry

Hmmm...I think there are a few possibilities.

1. You still have an air leak.
2. Your feed rate is higher than you think. (count how many times the check pawl clicks during the downstroke)
3. Your coal is undersized (or contains a lot of small pieces ) and is restrictive to air flowing up through it.

It sounds like you painstakingly assembled the stoker with new gaskets, so let's assume there are no big air leaks. If the boiler produces enough btu's to meet your needs and doesn't overheat, leave the feed rate alone and bump the air up to ~5.5, then repeat your experiment. You want about 1.5-2" of ash around the fire.

I'm having the same problem now. How do I adjust the plates? Thanks.