Here's an update: checked the gap on the ignition coil and adjusted it to .010 which seemed to even out the higher idle so now it's good at low and high but surging in the middle. I feel like the problem is in the governor linkage. I can't find a picture of what it should look like to compare...
Inherited this tractor with a home purchase last year. Seems to be about 20 years old from some of the paperwork I found. Once we took ownership, I went ahead and completed the following:
- oil/filter change
- new belts
- fuel filter
- air filter
Ran fine until this year. I was out mowing and...