Here's a trick I tried to help out a similar situation I had. My stove was getting huge clinkers after about 8 hours when I ran it on the higher settings.
I lifted the plate out of the pot, took a small bunch of coarse steel wool and stuffed it into one of the holes in the sides of the burn pot down at the bottom. The holes on the sides allow the air to come out the small line of holes at the top of the pot.
This forced more air to be drawn through the plate in the pot and practically eliminated my clinkers immediately. This will work for all fuel feed rates and should help your problem. There is still a small amount of air coming through the line of holes, but it is dramatically reduced.
You will be forced to play with your low end settings again though (I'm currently at 3-1-1)
Try it out and let me know how it works for you!
Good Luck!
I lifted the plate out of the pot, took a small bunch of coarse steel wool and stuffed it into one of the holes in the sides of the burn pot down at the bottom. The holes on the sides allow the air to come out the small line of holes at the top of the pot.
This forced more air to be drawn through the plate in the pot and practically eliminated my clinkers immediately. This will work for all fuel feed rates and should help your problem. There is still a small amount of air coming through the line of holes, but it is dramatically reduced.
You will be forced to play with your low end settings again though (I'm currently at 3-1-1)
Try it out and let me know how it works for you!
Good Luck!