Cam Melted on My Keystoker Koker

Came home from work today ~75 degrees outside. Came in the house and I heard the furnace come on. Noticed a smell of burning plastic, looked inside the firebox and there was a 1" wide line of flame along the right side of the stoker. Coal was also burning pretty far back on the grate. Looked in the back at the gear motor and pusher. Looks like the cam melted and probably the nylon guide screws.
I just lit the furnace off a couple of weeks ago so it's fairly clean (thoroughly cleaned in the spring) and when I checked draft it was good -.05.
Anybody else experience this? Why did the cam melt?

Furnace is direct vent.

Charlie

Where you seen a line of fire there was a good supply of air...where you see raw coal unburned there was little to no air.

Check if the grate is fully seated on both sides and in the rear, gaskets need to seal to keep even fan pressure up through every grate hole.

Don't know what it was like at your location today, but it was very windy here most of the day and that plays 4ell on a chimney or power-vent.

And do you use a barometric damper?

Sounds like an air leak/bad gasket like McGiever said, or too much draft and it's pulling it from the back of grate or hopper area causing it to burn back on the grate.

Do yo have a Draft Gauge? (manometer). and the draft of your direct vent setup properly.