For once, instead of being the guy answering engine questions, I get to come to my good friends and neighbors on here with the hope that you all collectively can save a Kohler K321 from getting a good load of buckshot in the gizzard.
I think we all have read the upteen gazillion Kohler engine surging issue threads all across the internet. However, this little K321 has a different issue.
The engine is running a Cub Cadet 149. It starts immediately, no matter what. It will chug along so slow you can nearly count each time it fires, and it will run wide open and lug down the thickest grass without sweating.
However, if the engine is sitting still with nothing to do, it will surge at full throttle. No little surge. It will stroke from idle to WOT back and forth.
So I start down my typical trail. First, we know the carburetor is adjusted right, and it is clean as a whistle... brand new clean since it just came out of a box! We know we have the right main adjusting needle.
As we all know, most surging issues on a Kohler are ignition related. I had already replaced the points, but we scrubbed them with a file just to be sure no manufacturing grease was clogging them up. New condenser. New coil. New spark plug and spark plug wire. The points are gapped .020.
That leads me back to the governor. I have a new governor spring on it. The governor is adjusted correctly on its shaft, and the sensitivity adjustments don't seem to do much good. I worried that the governor gear was spun on the shaft, but since I see how well this engine lugs down and pulls under a heavy load, and responds very well, I don't see how that can be. Usually a gear issue will result in surging or overreving all the time.
So now we are back to fuel. My guess is that the engine is running too rich. However, screwing the needle around doesn't do diddly squat, beyond literally blowing the tail off the muffler during one nice bang!
I wish I had a dollar for all the K321's I've rebuilt, repaired, or sold. But this one has done me in. We've been through two tanks of gas together but now that I need a muffler so my hearing will improve does not improve my love affair.
So, before the trusty Winchester comes out and gives this engine a final coup, does anyone have any last words?