Stumbling Kohler

[bertsmobile1]

First let me say that I am by no means a professional mechanic. A neighbor with a Dixie Chopper Kohler CV20 was mowing and engine quit running. He assumed it was the carburetor and purchased a new one but still wouldn't start. When it got to me, checked for compression and found one cylinder was reading zero. Pulled head to find that intake valve had been dislodged and setting at an angle not allowing valve to close. Replaced head and when engine would not fire, found fuel tanks to have water in them from mower being stored outside with a broken fuel cap. Drained tanks and engine started and ran fine. After about a month, got a call to say mower again had quit and wouldn't fire. Pulled plug from replaced head and found electrode to be smashed. Again pulled head and something made from metal (never found), had gotten into head and caused extensive pock marks to head, valves, bent both pushrods, and smashed top of piston to where it locked rings. Replaced piston, push rods, and took head to local machine shop and after inspection, it was determined that even with marks, head and valves were ok to use. Compression on repaired cylinder is 120 and other cylinder is 140. That pretty much takes us to today. Mower will start and run fine. When PTO is engaged, it acts like it has a miss and won't quite build the rpm's to smooth out.

I you still have the old carb checkthe bolts that hold the throttle / choke butterflys onto the shaft,
They have a bad habit of dropping out.
As for the current problems, try squirting some starting fluid down the carb, if you can keep it running smoothly then you have a fuel problem.
If not then look at the coils very carefully check both the high & low tensio wires for shorting .
If this engine has an oil alert system fitted that cuts the motor in a low oil situation, check the oil level then disconnect it and see if that is the problem.

 

[coinman66]

First let me say that I am by no means a professional mechanic. A neighbor with a Dixie Chopper Kohler CV20 was mowing and engine quit running. He assumed it was the carburetor and purchased a new one but still wouldn't start. When it got to me, checked for compression and found one cylinder was reading zero. Pulled head to find that intake valve had been dislodged and setting at an angle not allowing valve to close. Replaced head and when engine would not fire, found fuel tanks to have water in them from mower being stored outside with a broken fuel cap. Drained tanks and engine started and ran fine. After about a month, got a call to say mower again had quit and wouldn't fire. Pulled plug from replaced head and found electrode to be smashed. Again pulled head and something made from metal (never found), had gotten into head and caused extensive pock marks to head, valves, bent both pushrods, and smashed top of piston to where it locked rings. Replaced piston, push rods, and took head to local machine shop and after inspection, it was determined that even with marks, head and valves were ok to use. Compression on repaired cylinder is 120 and other cylinder is 140. That pretty much takes us to today. Mower will start and run fine. When PTO is engaged, it acts like it has a miss and won't quite build the rpm's to smooth out.

Did u check carb throttle and choke shaft to see if it's missing one of the little brass screws that hold the choke and throttle plate on? Had that scenario happen to a friend. It bent his valve.
Let us know

 

[Lawnranger]

Just ran it around the yard a few times and it is almost acting like only running on one cylinder, however, both plugs are getting spark.

This little beauty just came into my shop with the same symptom as yours. Have a good look at the intake gasket in this picture and note the mounting surface in the background. Think this could cause a problem? Engine ran, spark on both plugs but since it has ingested so much dust & dirt the cylinder leakage is now over 55% - time for a new engine.

Guess how I found the leak? Hint: mentioned in a previous post in this thread.

 

[ghost1]

Update:

Replaced intake manifold gaskets and resolved the issue... Thanks to everyone for advice