I have a Craftsman 42" riding mower with a Kohler engine. It runs great for about 20-30 minutes then quits as if it ran out of gas. I have cleaned the tank, fuel lines, replaced the fuel filter, the air filter, replaced the oil/filter, spark plug, battery, checked all the wring. It will turn over but not start, so it doesn't indicate a safety switch issue. If it sets for 45 minutes to an 1 hour it restarts, runs fine for another 20-30 minutes and does it again. What could I have overlooked?

The Lubrication! Could be overheating, change oil and filter, fill to PROPER levels. Possibly its just cooling off and then working OK? Just a thought...

It sounds like a vapor lock. Check the fuel line to see if it is touching any hot part of the engine. Try to stick the fuel line up away from any hot spots. Thomas

I have a Craftsman 42" riding mower with a Kohler engine. It runs great for about 20-30 minutes then quits as if it ran out of gas. I have cleaned the tank, fuel lines, replaced the fuel filter, the air filter, replaced the oil/filter, spark plug, battery, checked all the wring. It will turn over but not start, so it doesn't indicate a safety switch issue. If it sets for 45 minutes to an 1 hour it restarts, runs fine for another 20-30 minutes and does it again. What could I have overlooked?
I have the same problem, and I've yet to solve it. I just started it it for the first time yesterday and now it dies after about 5 minutes. I let it sit overnight and it statred right up this morning, then died 5 minutes later.

I've cleaned the carb, checked all wiring... nothing seems to help. DId oil change and filter work for you. I didn't think of that?

Is the battery fully charged? The fuel cut solenoid under carburetor will fail under low volt situations.

Don

Good answer Newaukumdon. Thomas

It was the spark plug wire. I replaced the "ignition module", (spark plug wire with coil attached) that mounts at the magneto. Runs like a new one. Thanks for everyone's input

Very good, it must be a relief to have found the problem without just replacing all the parts..

Don

I wanted to add that I had the same problem as Sabradon on the same lawn tractor and it was fixed by replacing the ignition module... I had also gone through the same routine he described... thanks to Sabradon as I did this as a result of his post on this website... my local lawn and garden store was clueless and told me I was likely at the end of the tractor's life (10 years) and the problem probably was due to something or other having to do with compression... I think he just wanted to sell a new tractorl. This website saved me a lot of money and agravation... thanks