Small Engines (Lawn Mowers, etc.): Engine Operation, new spark, fuel flow

Question
Dear Sir:
My brother has a Sears riding mower, 16.5hp. when starting it, It runs for a bit then dies. The fuel has been dumped and fresh added, new spark plug, fuel filter is see thru type and appears to be clean, fuel is flowing from the line to the carburetor just fine. Any suggestions as to what might the malfunction be?
Any suggestions will be heeded...
Thank you
D

Answer
Hi Darrell,

When it quits, check to make sure that there is good spark at the spark plug.
Then, we need to determine if there is a lack of fuel flow to the engine. Squirt fuel or starting fluid into the carb intake to see it it can be kept running.  It it runs, then there is probably dirt, debris or gummed fuel in the carb.  It would need to be removed, disassembled and cleaned internally, including all the small openings.

Let me know how things work out.
Michael