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Discussion Starter · #1 ·
Greetings:

I'm trying to get my new (to me) 757 Z-trak back running again. Based on the issues outlined in the forum in various places, I took the shields off of the heads and front in order to clean the head fins. Indeed, while they weren't totally plugged off, several fins had obstructions of greasy dirt. So I cleaned everything as best possible and reassembled.

While doing this work, I noticed that the governor appeared to be mal-adjusted, the linkage would move only very slightly, just a bare bit. I.e. the governor arm was adjusted on the shaft in such a fashion as to prevent any movement at all of the governor throttle plate. Turns out this is the main throttle plate in terms of power...

Before disassembling, I had the mower out in the yard and found that when I would engage the blades, the RPM's would drop. They drop again when the hydraulic pump is turning the wheels...

So based on this, I've adjusted the arm on the shaft to allow for full movement of the throttle. I start the motor to test the re-assembly and find that the governor is not working to control the RPMs. The arm appears to be dead, there's no force moving it as a function of RPM.

The last service the mower had (JD dealer in Oct. 2011) stated that the mower would not idle down, and that the governor was out of adjustment, so the tech adjusted the governor...

I'm thinking that the plate on the inside of the housing has come off/loose... Anyone able to opine on the symptoms?

Much Grass,
 

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Discussion Starter · #3 ·
Greetings once again...

Thanks to Mark - who sent along a link to the service manual for these engines (FH721), I was able to set the governor shaft on the arm properly, and VOILA!!! Now the governator pulls quite strongly at high RPM's. She Works!!! So - now I'm re-installing the throttle control plate and adjusting according to the manual. When it warms up in the next day or so, I'll have a chance to go out and finish that task - and I should be ready for mowing season.

Again, what happened is that I bought this from a JD dealer and when I got it home noticed that the engine didn't appear to have much reserve power. When I'd engage the blades at WOT, the RPM's would drop noticeably. When I would then put the rig in motion down the yard, another drop in RPM's. During disassembly of the head shields for cleaning, I noticed that the governor was adjusted in such a way that no to very little movement was permitted. The last service ticket that the machine had at the dealer's showed a governor out of adjustment and the fixing of that issue. I'm thinking this is why the machine seemed not to want to return to the revs once load was put on the engine.

Thanks to all who chimed in here. These forums are absolutely GREAT!!!!
 

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It is unfortunate the dealer let that out the door that way. They really should have caught that if they had run the blades and drove it a bit. But great to hear you were able to get it adjusted back proper! :cool:
 
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