54" Bobcat Walk Behind Hydro 930323 speeds out of control

[Jorjo]

Please help! I just purchased an older Bobcat mower and it runs good. Engine throttle control works fine. However, the Hydro Speed Control does not. If I start out slow, it will slip up to wide open in a matter of seconds once I start moving. The control is just really loose and I can't seem to find an obvious way to tighten this control up. Any ideas are greatly appreciated.

Thanks!!
Joe

 

[StarTech]

Model no. would be helpful.

the model was postedin the thread title. It is 930323. Only found it on Jacks. The Hydro Gear pump would be needed as Bob Cat appears to not offering parts for them anymore.

As for the problem I haven't ran into a ZTR with similar pump setup that was doing this so I am of no help here. But I am it is a check valve problem and that is just an out of blue guess.

 

[bertsmobile1]

As it's an "old" bobcat I would be looking closely at all of the linkages and checking them for holes flogged out oval
The controls at the box do not move very far from 0 to flat chat
In particular look at the mounts for the pedals they seem to wear the most
A rough test would be to put a spring on the arm at the transmission pulling the lever full back and a length of string so you can pull it the other way.
If you can control it normally with the string then it is a linkage problem
If it is the same with the string then it is a transmission problem.
Also check the clutch / brake system.
If the pivot points are flogged oval it could be the belt self tightens in operation causing it to pick up speed .

 

[Jorjo]

Thanks guys for all the suggestions! I will check this all out in more detail this weekend and let you know what I find.

Joe