DIAGNOSIS The carburetor's main jet or passages are clogged with old gas deposits. The engine runs on the fuel in the float bowl, then starves.
FIX Clean the carburetor. Drain all old fuel from the tank and carburetor bowl. Remove the carburetor bowl (usually one bolt on the bottom). Spray the main jet (the small brass piece with a hole in the center) and all visible passages with carburetor cleaner. Reassemble and fill with fresh, ethanol-free gas if possible.
IF THAT DIDN'T WORK The fuel filter in the gas tank might be completely blocked. Disconnect the fuel line at the carburetor, check for flow. If weak, replace the in-tank fuel filter (Part Number 16955-Z0L-015).
HEADS UP Always use a fuel stabilizer if storing the mower for more than a month. Ethanol-blended fuel left sitting is the primary cause of these carburetor issues.