Small Engines (Lawn Mowers, etc.): 15 hp kolher, 97 craftsman tractor, compression test, fuel cap

Question
Runs like a champ for up to 40 min or so. Stalls and will not start. When attempting to start engine backfires thru carb. Let sit till next morning and same thing again. Noticed this happened once or twice at begining of season but went away. Thought it was bad gas.

Answer
Hi Denny,

Check the fuel cap to be sure that it is venting.  The backfiring indicates either an advanced timing problem or more likely, a leaking intake valve, maybe due to a spring that gets weak when heated.  Do a compression test when it quits.

Let me know what you find.
Michael