First off, did you check the exhaust pipe and make sure it's clear.
Did you clean under the grate where the coal burns.
Before you loaded the hopper with coal did you check the grate and make sure it was smooth and flat, no warping.
Before you did anything did you check the fans and make sure they were clean and oiled.
Did you check the stoker to make sure it would move forward and back and push the coal.
looks like a Alaska 140 to me but man have I been wrong before, lol.
Don't worry help is on it's way here just stay tuned