I just started having a problem that when running the mid mount mower that the engine will bog way down. If I cut the PTO the engine recovers to normal RPM. The weird part is that it will mow for about 20 sec - 1 min, then bog. I tried it with the mower up and there is no change. The first time it happened it only lasted a few minutes, then I was able to mow the rest of the lawn (2+hrs) with no issues. Today the problem seemed more severe, so I parked the tractor and thought I would look for causes.
Here are the three things I was going to do:
New Fuel Filter (About Due)
Change Hydrostatic Fluid and Filter
Check individual spindals on mower to see if a bearing is going bad
Any other ideas?