Outdoor Power Equipment and Small Engines - kohler command governor problem

I bought a used Craftman riding mower with a Kohler Command vertical shaft engine, about 20hp. The engine races out of control and the throttle has no effect on teh engine speed. I can manually bring it to idle by sliding the governor linkage that is located below the carb. The governor linkage does not appear to work correctly with the throttle linkage but I am unfamiliar with how they are supopose to be connected. The old owner stated he took the tractor to Sears service and they indicated it needed a new governor. My questions are:

* Could the governor and linkage simply need an adjustment? How is this done?
* How does one replace the entire governor mechanism? Does this require dissassembly of the entire engine?
* Does anyone have service manual instructions on how to do the above?
* Any other thoughts on what could be wrong?

Thank you!

Chances are if they say it needs a new governor, then it probably does. It's not all that uncommon on kohlers. The engine has to be removed and the sump cover removed to replace it. It's not a hard job though. If you feel no movement or force on the governor lever in relation to the speed of the engine, then the governor is bad.