Craftsman 37299 21" 132cc Push Mower won't start.

Craftsman 37299 21" 132cc Push Mower won’t start. I’ve only mowed the lawn 3 times. I would guess it had some stale gas in it I’ve drained the gas, changed oil, changed spark plug. No luck. Added seafoam to gas. Sprayed starter fluid in carb. No luck. Will start for a few seconds then dies. Gas drains out of the carb ok, so fuel is flowing. Fuel filter looks ok. Any ideas?