Did You take the vac reading using the choke? Having the choke on will give a false vac reading less air thru the carb but pulling gas into the cly. Try and take the vac. when there is no choke on ,if the engine will not run than it has to be a vac. leak some where ,it's a pain to put new gaskets on but You can check both the intake and the head surfaces when it's apart.
Pete
