Mower stops running when hot

[atombaum]

Mower starts up, and runs fine when cold. Runs anywhere from 10 minutes to 30 minutes before the revs decrease, and it stops. It starts up again after it's cooled off.

• New coil
• New plug
• New air filter
• Full tank of good gas

Any suggestions on what to check?

See this topic for photos of mower, etc. See signature for model number, etc.

 

[bertsmobile1]

The instant it stops spray a SHORT shot of carb cleaner down the carb throat
If the engine fires right away then you have a fuel supply problem so remove the fuel tanks and clean them out, replace all of the fuel lines then remove float bown & clean it.
Flush the system out with good fuel and hook everything back up.
If it does not run, check the spark
No spark = bad magneto coil
Spark = overheating , remove the blower housing and clean the cooling fins then when cold readjust the valve lash.

 

[atombaum]

Ran for five minutes, and it stopped. Checked for spark after it stopped, and no spark. The coil had been replaced earlier in the summer for the same problem. Turns out there are several coils for the Kohler XT149. Found "the" coil, and replaced.

 

[atombaum]

FYI - the correct Lawn Boy coil: Kohler module 14 584 05-S Alum Std Ignition.

 

[sgkent]

Glad it worked out. I stop working when I get hot too. Don't know what the problem is. Think it is an age thing