Engine:
Kohler
Family: SKH426U1G2RB
Model: CV15S
Spec: 41450
Displ: 426
Serial: 2606614633
Carburetor: Walbro

I have a JD riding mower with the engine listed above. It will crank up, run fine for about 1-1/2 hours, then start sputtering. When it starts sputtering, there is no fuel in the filter. You can stop, put it on full choke, it about dies, pull off choke and back on choke again until it about dies, pull back off again and fuel will run back into the filter until about 1/4 full. It will run a little while longer and do the same thing again.

I have replaced everything from the tank to the carburetor, removed tank, blowed it out with air and saw no problems. Also have new gas cap. You can take the line off at the carburetor, put it in a jug and it will drain the tank. The carburetor has been rebuilt, blowed/cleaned out. The only thing I see wrong is there is a little wear/slack on the governor rod (the one with the butterfly that goes through the carburetor). The carburetor kit does not offer this part is the reason I did not replace it.

I have the fuel line running from the tank to the carburetor at a downward angle.

After you let it sit for about 5 minutes, the fuel filter will fill back up. The air filter is clean. The spark plug is good and clean. There is no blue/black smoke at all, even when sputtering. I have checked the float in the carburetor and it was not cracked that I could tell (no gas in the float).

Please Help!

 

Have you tried a new fuel filter? I had a mower about a year ago that I installed a new fuel filter on it and it started doing just like yours, turned out to be the fuel filter.

 

I agree. Use one specifically for kohler, or use a briggs screen type filter. For some reason, universal-type filters don't seem to work well with kohlers.

Another thing to check is the gas cap. Try loosening the cap when this happens to see if the filter fills back up.

 

You can also try reversing the fuel filter if it's aftermarket. There are a few out there that flow better one way than the other. Why? I don't know. Also examine the filter to see if it has a directional arrow and is it pointing in the correct direction of flow.