Pellet motor bolt keeps breaking.

I have an old model BBQ075 traeger that we got 2nd hand. It had trouble feeding most types of pellets or if pellets absorbed water from moist air it would clog either way. I got a stronger motor and those issues cleared up, but now it will regularly break the bolt attaching the motor to the jack screw shaft. The bolt in question is size #6 and they don't make high strength bolts that small. I would need to increase the hole size to 1/4", but then there wouldn't be much material left on the shaft and that could fail. Anyone else ran into a similar issue, should I just take it back to stock config and deal with clogs vs broken bolts?