Three days ago while at the breakfast table  I heard the oil burner come on. Ot Oh!! That meant no coal fire.Not only that ,black coal was filling the ash bucket area and overflowing the stoker.It was certainly trying to make heat with no fire,probably all night. I re-etablished fire and noted a very wimpy standby fire.The fire was not even making it all the way across the width of the grate area.I increased the pins to make 4 pins every 10 minutes.It stayed running but today was beautiful with minimum call for heat . I checked it just now and it was very skimpy again.There was a lot of standby time today. The coal is UAE and I am right in the middle of the last load and it is good coal, good ash and good heat when needed. My question is this: Is it possible to wear out one of the nylon(?) eccentric discs that actually pushes the feeder block? I don't know what else to think,has anyone else ever had a problem like this one? Thanks for your thoughts. MIke
I'm thinking along the same lines Mike; Air Flow........ Either grate holes blocked, or furnace cement had fallen out, allowing air to take the path of least resistance, and not be forced through grates. I pulled my stoker completely out this year. Went all through it. Works like new. I did notice wear on the nylon pusher wheel. Oliver
I had same problem once with my keystoker pull grate out and vaccuum out the fines .if you pull the pusher bar out and find the nylon screws worn [or in my case two were broke] just go to lowes or home depot and get them but seems like air flow issue like the others said .