Hi Gary,
Remove and disassemble the carburetor for a thorough cleaning, ensuring all jets and passages are clear.
Check the spark for strength and consistency, especially after 5 minutes of running, just after the engine dies .
Perform a compression test.
Verify the fuel flow from the tank to the carburetor ,some mowers have a fuel strainer in the bottom of the tank or a fuel filter.
Cheers
Max.
