Small Engines (Lawn Mowers, etc.): mower misses when hot, briggs and stratton, riding lawn mower

Question
My riding lawn mower starts fine but begins to miss and sputter after it is at running temperature and eventually stops. This only happens after the engine is warm. I have changed spark plug, oil, etc. and no change.
It is a basic 13 horsepower Briggs and Stratton engine.
Thank you for any possible assistance.

Answer
Hi Doug,

You will need to determine if the problem is a lack of spark or a lack of fuel flow.  Right after it quits, remove the spark plug, reconnect the wire and lay it against the engine head.  Crank the engine over and watch for spark at the plug's electrode.

If good, then try to start it while squirting fuel or starting fluid into the carb intake.  If it starts, then the carb most likely has dirt, debris, gummed fuel or water inside.  You will need to remove the carb, disassemble it, clean all the small internal openings and blow it out with compressed air.

Since your mower only quits when warm, I suspect the problem is spark and not fuel.

Let me know how you make out.
Michael