I was getting ready to leave the blind this morning and had the engine warming up, then all of a sudden it starts reving really high up to about 4800 to 4900 RPMS. So I shut it off and restarted it and the same thing happened. Thought it might be a throttle cable frozen but everything was moving fine. Well I had to get out of their so I just started it and threw it in gear real quick, which seemed to work but then it wouldnt go above 3400 RPM while I was running it. Ended up stuck in the middle of the lake when the motor quit, I tryed starting it back up and the motor is making really bad sounds like a gear wheel is hitting something. ANY IDEAS WHAT THIS COULD BE and why it started reving really high with no throttle?
Its a 27 Kohler PD with no mods.

it is most likely issues with your govoner, because one of my friends had that same problem with his 23hp vanguard, and i fixed it. but if you are hearing grinding noises it possible that somethin could have gone bad in your block!! might want to contact that dude rod wit coondik customs on here an he could tell you more.