Likely a stuck needle in the carb. Pull off the fuel bowl and unstick it. The float isn't pulling the needle off of it's seat. You might try draining the fuel out of the carb, then tap the carb LIGHTLY with a plastic screw driver handle.
By draining the carb after use and squirting some WD40 into the fuel inlet, you'll prevent that.
Shouldn't be a big deal.
Ask me how I know that??!!
Listen to what the folks on this forum recommend. You'll save yourself a lot of headaches in the future.
Clark Gaynor Sr.
Not knowing what kind of fuel tank you are using, but it could also be the fuel pick up tube inside the tank. Sometimes they crack and break off. If there is no fuel pick up line issue inside of the tank or fuel line issue to the pump, then check for a stuck float needle in the carb. If that doesn't fix it the fuel pump is probably bad and then check valves and try to start the engine.