I loaned my push mower out for the season last year, had to get it back this season, it was not winterized, nor properly stored, so it wouldn't start much less run. I cleaned it up, changed oil, drained gas and refilled (adding STA-BIL), installed new spark plug, air filter, air filter gasket & took the carburetor completely off and cleaned it well (including bowl & nut) with carb cleaner, (float & pin look brand new). Reassembled it, and now it will start but sputters and stalls if you try to mow. What else do I need to check?