78 johnson fuel pump, extra hole?

[shawnswan]

I just bought this motor and notice when pumping the bulb, there's gas spurting out a little hole in the back of the fuel pump. I took the fuel pump apart and it looks like the hole is intentional. All the springs and seals seam to be there. When the motors running on the lake there's a pulse of gas that comes out about every second. In the parts catalog for this motor there are only two lines that connect to the pump. Does anyone know what this is for? Do I have the wrong fuel pump?
Thanks.

 

[Joe Reeves]

Re: 78 johnson fuel pump, extra hole?

Fuel coming out that hole indicates that the pump diaphragm is ruptured. If a kit is available, rebuild it. If not, buy a new pump.

That type pump is operated by crankcase pressure being directed at and thru that hole. There should be a thick gasket on the back of it that corresponds to a similar hole in the crankcase.

NOTE..... always list what engine you're speaking of so that we can look up what type fuel pump you need, otherwise we don't know if you have the proper pump or not.

 

[shawnswan]

Re: 78 johnson fuel pump, extra hole?

Sorry, the motor is a 55hp.
The gas isn't leaking out of the bottom hole where the gasket is. There's a little hole on the back of the pump near the top. I'm assuming that in either case a kit or a new pump will be required.