WE have a Mercury 500 50 HP with thunderbolt ignition that the bottom caruretor is pouring gas out of the copper bolt that holds the bottom of the caruretor, the top one drips from the same spot. We suppposedly had it rebuilt but when we got it back it was worse than before, all the boat place near us want to charge more to fix it than it is actually worth, so we found one on e-bay with a serial number close to our. Our serial number is 4806224 and the one we found on e-bay is 4118963. Does anyone know if this one would work for us, because I was told that more than likely because of where they are leaking they were either stipped or corroded. Any advice would be appreciated. Thanks for your help.