Seems a few have had a problem with improper burning on the grate, too close to the feed, smoke from hopper or a hopper fire....Ref. http://nepacrossroads.com/post14674.html
Well, here a pic of my Keystoker 90K grate. I am in the process of moving it, so I figured I would do a little cleaning and document it for everyone.
First Shut the stove down and let it cool for a few hours or overnight. The coals still may be warm!!
1. Clean the coal out as much as you can out, shovel, etc...
2. Vacuum the rest out. Use a Nylon Paint brush to brush the ash, coal out.
3. Remove the Bolt/Screw on the RH (Right Hand) plate
4. Scrape/Cut the sealant around the RH plate.
5. Gently Pry up from the front and Remove Plate
6. Clean the Combustion holes on both sides (small drill bit or piece of wire works good).
7. Clean/vacuum UNDER the plate really good, you will get alot of fine coal dust under it and will affect the burn.
You may put your vacuum in the section below the plate and turn the combustion blower on to move some of the dust/
ash into the vacuum.
8. Re-Install the RH Plate
9. Bolt it down
10. Apply a liberal amount of Furnance Cemet (Pipe Cement) rated for at least 1000-1500 Degrees. Any place that sell Wood/Coal stoves should have it, make sure you put enough along the back part towards the hopper and along the sides. Prevents the fire from spreading from where it really should be burning (Burn area noted in pic).
You shouldn't have any combustion air except thru the holes. It shouldn't burn any farther back before the air holes unless you have an air leak.
Enjoy your spring cleaning!