Raider 12 carb fix.

[Ed Kennell 42,111]

The  Raider 12 shares the mowing duties with the C-120 and now the 312 hydro.  Late last year, the Raider started running poorly... no power and requiring full choke to run at all.

So yesterday, I pulled the carb ( Carters 26) and was really surprised at  how clean it was. It appears the Sea Foam and Sta-Bil are doing their job.

With the carb off, I did crank the engine to verify I had a good fuel supply from the pump.

  Of course I flushed all holes with carb cleaner but really didn't find any dirt.    The other known problem was the throttle shaft was loose in the carb.  So I decided to remove the shaft and install a  bushing.  If you ever do remove the throttle plate screws, remember to file or grind away the back side of the screws as they have been crimped to prevent loosening and they will break off if  you try to remove them without removing the burred up threads.

After removing the shaft, sure enough, the shaft was worn and loose.   Simple fix is to press in one of the 1/4 X 7/16 X 1/8 inch bronze bushings that I bought from Brian Miller several years earlier into the counter bore where the seal was located.       Now...where did I put the bushings ?      I finally gave up and went to ACE but all I could find was a 1/4 X 3/8 X 1 inch bronze bushing.

Not wanting to wait for a new supply of bushings from Miller, I set up the carb on the drill press using a 1/4" piece of drill rod, then drilled a 3/8" hole 1/2" deep and pressed in the bushing. Then cut off the bushing flush with the top of the carb so some of the unworn part of the shaft is in the new bushing.

The raider now starts and runs full range with good power without any choke at all.       Sorry, I didn't take pics, But If you go to Brian Millers web site, he has all the details on how  to make this repair.

[953 nut 60,251]

Ed, you explained the process clearly enough that no pictures were needed.    

[Ed Kennell 42,111]

Thanks Dick,  the actual reason I posted this fix was to try to impress the importance of having a good seal around these throttle shafts. 

  This is the 4th poorly/barely running Kohler I have brought back to life by making this easy fix and I suspect this is one of the main fuel related problems.

  It is amazing how much such a small air leak can affect the performance of these engines. 

   I do recommend buying the 1/4 x 7/16 bushings that press into the existing counter bore. 

  Drilling the carb to use the 3/8 bushing as I did is risky as great care must be taken to perfectly align the carb to keep the newly drilled hole concentric with the existing shaft hole.