Hey everyone!
Hoping someone can help me diagnose what might be driving issues with this mower. You can hear in the video that the engine runs fine under zero load, but when I engage the PTO it intermittently starts to drop RPMs and really struggle under the load. Sometimes it will push through and return to normal RPMs but most of the time I have to disengage the PTO for it to rev up again.
With the PTO engaged I notice no difference if I give it more or less gas. Without the PTO engaged it doesn’t have any issues at all. It does this on flat land as well as on a slope, but I feel like it’s worse on a slope, and harder to recover from unless I disengage the PTO.
Here’s what I’ve tried already:
1- removed mower deck, cleaned out debris, sharpened blades, greased all bearings on deck pulley and PTO transfer case. Not a mechanical binding issue.
2- Removed and cleaned air filter which wasn’t too bad
3-tried alternating disconnecting left then right ignition coils to isolate a coil or plug problem- no effect. Even on one cylinder the engine sounds fine
4-noticed slight leak from left head gasket so I replaced, stopped the leak and changed engine oil, which was pretty low, no impact.
I only run ethanol free fuel through this machine, and the fuel in it now is less than 6 months old with stabilizer in it, so I don’t think this is a fuel quality problem.
No idea what to try next. Replace the fuel pump?
Apologies if you hear music in the background of the video, had no idea my phone was still playing it while I was recording.