Small Engines (Lawn Mowers, etc.): Craftsman Rider, throttle linkage, throttle cable

Question
I have a craftsman riding mower, 18 hp, and when I was mowing the engine throttled up and I could not lower the rpm's. I tried to manualy move the throttle linkage on top of the carb and still no results.  No matter what I moved (except the choke) nothing would have an effect on the engine.  My throttle cable is working fine. Thanks,
Terry  

Answer
 Hello Terry:

 From your Description it could be a Broken Governor Inside the Engine or the Governor Control Spring. Send me the Model Numbers Off of the Engine, Please. With these Numbers I can View a Breakdown of the Engine and Better Assist you. Hope this Helps. Let me know what Happens, Please. Thanks.

 Good Luck

 Respectfully

 John