information on the engine brand / model / type, code or spec is needed.

If this is the large displacement Briggs Quantum series, chances are your fuel leaking problem is not caused by the primer bulb. The primer bulb is simply an air pump. There is a vent located on the end of the bulb. When depressing the bulb air pressure is forced into the carburetor float bowl. This forces fuel in the float bowl to travel up the venturi tube and enter the air stream into the engine. Carburetor flooding may result in fuel entering the primer bulb.

Usually a screwdriver is used to pry out the metal ring holding in the rubber primer bulb and a 3/4" socket and hammer is used to install the new ring. Use care when removing the ring.

BTW, IF YOU HAVE THE BALL SHAPED BULB PRIMER (RED USUALLY ON MY CHEAP MOWER)AND IT HAS A SPLIT IN IT THERE IS AN EASY FIX IF YOU CAN'T FIND A REPLACEMENT AND IT INVOLVES THE SILICONE RUBBER IN A TUBE THAT YOU USE TO FIX A LEAKY WINDSHIELD(AUTO STORE WILL KNOW), ALTHOUGH THE THICK TOOTHPASTE-LIKE SILICONE RUBBER WILL WORK. JUST PAINT SOME OF THAT ON THE ENTIRE SURFACE OF THE BALL AND RECOAT IT WITH RUBBER, USING A MATCHSTICK OR EVEN AN OLD BRUSH. THIS WILL SEAL ANY HOLE OR SPLIT IN IT AND YOU CAN CONTINUE TO MOW RATHER THAN MAKE A TRIP OR WAIT FOR THE MAILORDER PART.

Hey speckspeck, why are you yelling?