Small Engines (Lawn Mowers, etc.): Briggs Stratton 8 hp on Snapper Engine Cuts Out, snapper rider, briggs stratton

Question
QUESTION: I bought a Snapper rider used 2 years ago with 8 hp Briggs Stratton.  It runs pretty well the first 15 min. I mow with it.  Then once the engine is at full operating temp. it starts acting like it's not getting fuel, running rough, then cuts out completely.  It will start only after I let it sit for several minutes and then cuts out within 2-3 min. I've keep clean fresh gas in it with Stabil. The gas filter seems to let fuel through when cold and I disconnect from the carb.  Have tried draining the sediment bulb. Symptoms are still the same. Ideas? Thank you. John

ANSWER: How old is the engine?  Look at the engine code number...the first two digits are the last two digits the engine was made.  89 for example indicated 1989.

I would replace the spark plug for starters and see if that makes a difference.

Eric

---------- FOLLOW-UP ----------

QUESTION: Eric,
Since I bought it used and I don't have immediate access to the mower to get the code (it's at a distant location)I can't give you the exact year. I think it's 12-14 years old.  According to the previous owner, he had regular service performed at a local mower service center annually.  
I'll see that the spark plug is changed and see that the mower blade is sharpened to lessen load on the engine.  I'm wonder if since it cuts out went the engine is hottest if that can cause interruption temporarily of fuel flow through the carb / intake?  Just before the engine cuts out, the governor goes up / down with the engine speed fluctuating fast / slow repeatedly on its own.
thank you
John K.

Answer
It could be fuel or could be spark.  That's the first thing you have to determine.

I suspect the ignition is electronic.  Electronic ignition is pretty reliable but it does fail once in a while which is why you need to replace the spark plug first to determine the plug is not faulty.

Eric