B2620 engine "stuttering" occasionally, sometimes stalling

[mike paulson]

The work I'm doing - dragging an arena and spreading manure - is all on pretty bumpy ground, so it seems like the shaking could be causing problems.
...

Bumpy, is it bumpy enough you're being elevated off the seat causing the safety switch to cut power

 

[jonsstihl]

look at your fuel filter bowl when it is cutting out. is it all cloudy and full of waxy substance.

 

[KillerBeagle]

Bumpy, is it bumpy enough you're being elevated off the seat causing the safety switch to cut power

Not quite that bad. At times I can replicate the issue by deliberately taking my weight off the seat; other times I can drive for a while with my weight completely off the seat, so it seems like the switch wiring is flaky.

 

[KillerBeagle]

look at your fuel filter bowl when it is cutting out. is it all cloudy and full of waxy substance.

Unfortunately I didn't look at it when the problem was happening. Later when I went to change the filter it looked fine, but it was warmer by then. If it was temperature-related, I'll probably have to wait until next winter to see freezing weather again.