Sounds like a fuel problem. REmove the fuel bowl, put a small container under the carb, turn on the gas and see if gas runs out without stopping. If it stops, you need to find out what stopped the fuel flow. I had a garden tractor do that and I found trash in the fuel tank. Cleaned the tank and no more problem.
Dennis
November 2008
Several possibilities, in order of likelyness (is that a read word???)...
1) Restriction in fuel line (dirt, deterioration, or both)
2) Float hung up (likely if stood with old fuel in it)