I go to meets with other members.(Mostly Steve Woods) We never have a problem because we add fuel when we are ready to use the motors. Then they are drained when we are finished so they never sit with gas in the tank. That said, it is very rare to have multiple fuel shut-offs leaking like that. On a hot day vapor pressure can over power a carburetor float valve, but a good shut off valve should be able to stop it. . . . . . . 😉
