Help me trouble shoot my Mt Vernon Non ae

Last week I had snap disc #3 go bad. Purchased a new one, thought things where dandy until...
I have the thermostat set at 76 and with the pellets i run it nevers reaches temp. premium grade pellets... It never reaches that temp so the stove runs continuously maintaining 72. Since it has gotten colder in the last week I tried to up the stove from #3 to the Quad setting #4 to get it a little warmer. Whats happening is that the stove is shutting down before it ever reaches 76 degrees on quad. The red call light is on but the stove stops feeding the pellets. If I wait a few minutes and then hit the reset button it will start dropping pellets again and continue on. I can run the stove on 3 setting almost all the time with the premium grade pellet. As soon as I run the stove on 4 it shuts down and If I add my good pellets on the 3 setting it will shut down. Seems its getting to hot...
I assume I have another bad snap disc or a faulty #3 snap that I just purchased. I ordered Snap #1 and #2 in hopes of "curing" the problem.
Any ideas guys?

Do you have the feed motor with the capacitor installed?

How do i figure that out?

Is it possible that your convection blower isn't moving enough air and the stove is overheating because it doesn't have enough room air moving through it. Check your convection blower for invasive dust bunnies.

Just vac'd out all the dust bunnies. I took off the side and exposed the auger motor and I have the original auger motor with the original wiring. I see the red capacitor. The new capacitor's would need to be spliced in or I buy a new auger motor with all new wiring....?

I would verify the operation of the of the control box lights and see if the red is staying lit and maintaining the required temps. I don't think it's the feed motor, but if you wanted to be sure, you can put power to it while it is removed from the stove and try to stop the auger. If it stops easily then the capacitor is shot, if it doesn't then feed motor and capacitor are fine.