Fuel running out from the primer bulb means that the carburetor is "flooding": the float bowl is overflowing. That means the float is not successfully pushing the tiny plastic needle up against its seat in the housing, to shut off the inward flow of fuel when the float rises due to a rising level of fuel in the float bowl. When this happens with a G4 it usually means that the needle has been omitted, or it has been put in upside-down - the pointed end of the needle has to go upward toward the seat, not downward toward the float arm.
(My involvement with G4s has never extended beyond the float bowl).
