[sturgis 39]

If there is vapor in the carburetor, the float would be at the bottom and the needle valve would be wide open and let fuel flow. The vapor pressure can not be more than atmosphere pressure. The column of gas from the tank to the carb is above atmosphere pressure. Maybe turning the mixture needle in would male it run better. I remember the local hoodlums would run the fuel through a can of ice in their race cars. I think I would try one of the canned ice packs used for coolers or sprained wrists or fingers.