Carburetor loses prime after 8+ hours

You might want to check your fuel lines from the tank to the carb. Today's gasoline is really hard on fuel lines and if you get a crack in the line, the fuel pump might not have enough suction to get going.

My fuel line was cracked at the very top right off the gas tank, couldn't see it laying under the car. Replaced the fuel line, and the fuel pump worked great.

Rod