It is a John Deere STX38 with a Kohler CV13 Engine. I can not get it to idle below 2200 rpm. I have adjusted the idle speed screw and idle mixture screw with no luck. I have also adjusted the governor (static) per the repair manual. There is some play in the throttle shaft but not that much IMO. The throttle shaft is resting against the idle screw as it should. I have had the carb off to check the throttle plate and it is there. I have even put an o'ring under the throttle shaft to make sure there was no air leak. I could really use some help on this one. I dont think a new carb will fix the problem -- do you folks ??

 

Take the carb off and look through it at a light with the throttle closed. Wherever you see light coming past the throttle plate is where the engine is getting too much fuel and air. The throttle is not sealing off all the way.

 

Thanks Cheese, I will try it.

 

Cheese as usual you were right on the money. Looked through the carb and saw light coming through. The butterfly was not sealing due to the top piece of the shaft being able to move around the shaft. I tried to peen it over but it didnt hold. I used red loctite to glue the top piece to the shaft and reset the butterfly and screws. Seems to be working fine. I used blue loctite on the butterfly screws. I hope they hold. Thanks again for your help.

 

Glad you got it! The shaft can be purchased separately and replaced if it doesn't hold.