77383,
Another reason your pucks may be feeding too fast is that the square hole the manual puck advance switch is mounted in may be too small, and therefore pinches the switch into the On mode continuously.
My puck advancer was in full runaway mode a few years ago. I replaced the switch with no change to the problem. Now I set my watch timer to 20 minutes, and when it goes off, I go out to the smoker, watch it cycle and stop, then add a puck to the tube. I only keep one puck in the tube, so if it goes crazy, I don't lose a stack of pucks. Good news is the last 5 or so smokes, it has never acted up.
I read on the forum here a while back that a fix for a pinched manual puck advance switch is to remove the switch, and make the hole slightly bigger with a file. I need to try that with mine, but never get around to it.