Float Bowl is Empty After Sitting
Some things to check for:
Percolation – Percolation can happen when your engine gets hot, then you turn the engine off and the fuel boils over, sometimes over the top of the carburetor, or more often, simply evaporates. Back in the day we called this vapor lock, which simply meant that the fuel turned to vapor before getting to the engine.
This has been a more common problem these days because our gas has a lower boiling point than it used to. Yup you guessed it, ethanol.
This makes it hard to start the next time. You have to crank and crank, or pour a bit of gas down the carburetor to get the engine started.
Fuel Tank – Is the gas cap vented? The wrong gas cap could cause a vacuum.
Leaking – Clean out plugs that might exist on the bottom may be leaking.
Siphoning – After turning off the engine look down the carburetor to see if gas is dripping from the venturi cluster.
Fuel Bowl Vent – Has any fuel bowl vent been plugged off?