TroyBilt self-propelled push mower won't start

[SteveLawnBoy]

All summer I have struggled with my mower. I started using "engineered" fuel based on a recommendation from a repair guy. My mower is stored in a back-yard storage unit. I live in Houston area, so very humid. I store the fuel in my garage. I only put enough fuel in my mower to cut the front and back yard, so it won't sit with a lot of fuel gathering moisture from the air. So fresh fuel every time! I mow once a week. Every time I start it, it starts on the second pull, but runs really rough for 5-10 minutes then smooths out and runs fine. Yesterday I did my normal routine of checking the oil and adding fuel. On the second pull it coughed but didn't start. It never even coughed again. I checked the spark plug and cleaned it. I checked the air filter - ok. I even drained the fuel from the tank, removed the bowl from the carburetor, and cleaned it. Added fuel back to tank and tried again to no avail. Help!

 

[dougand3]

List the engine model # - may be on a shroud near the muffler.
List the mower model # - on deck somewhere.
In general, sounds like a fuel delivery or choke problem - esp if air vane/thermostat choke.