MF 165 Governor problem

I think I have a governor problem on my MF 165. I joined this forum hoping someone can point me in the right direction. I live in a pretty rural place in Arkansas and there are not many tractor experts around unless I travel very far and bring my tractor with me.

PROBLEM:
When I'm running my brushhog on my PTO, and I hit a large patch of brush, the throttle is brought down because of the resistance the brush hog encounters. I have to manually push the throttle back to PTO level to get the speed I was running in before. I have to constantly raise the throttle to keep it at PTO speeds.

For me, this isn't a big deal BUT I just purchased a used M14 Foley Belsaw saw mill that is PTO driven. This presents a problem because everytime the saw hits the log, its going to drive down the throttle of the PTO because of resistance and someone will have to run around to the tractor to raise up the throttle again before the next board is cut.

QUESTION:
Can anyone provide a diagram for the MF 165 governor so I can see if anything is missing?
Can anyone suggest what may need to be fixed to correct this issue?

My only option as of now is to just jerry rig the throttle with a bungee cord to keep it at PTO levels but I don't like jerry rigging things as a rule. I want them to work as they should.

Hope you can help. I can post pics if you want.

We need to know what engine you have first, if its a gas engine it maybe either a Continental G176, or a Perkins AG4.212

Oh, I'm sorry, I thought all MF 165 were diesel. It's a diesel. Let me know what other info you need. I was under the assumption that my engine was a perkins.

It doesn't sound like a governor problem to me. Especially being a diesel. There is a friction disc on your throttle lever is shot or needs tightening up. Follow your lever and you should find a "star" shaped washer. Disc is under that.

Awesome,thanks, I'll look for that and report back.

The 165 throttle friction disc is at the lower end, take a 1/2 inch wrench and turn the cover plate nuts a little each will tighten it up IF the shaft and steel plate inside are OK. Over time the shaft and plate wear, causing excess play. On those I've welded the shaft to the plate, but it's tricky to do though keeping everything square as possible.