fuel lines 1980 2.5L 120 hp Mercruiser

[JimboFisher]

I am restoring a 1980 Citation boat and I removed the electric fuel pump to go back with the stock manual fuel pump. It looks like the manual is Camshaft driven. There are 3 ports on the manual fuel pump. I see the (out) to the carb and opposite the out is a threaded port but on top of the pump is a metal tube that I assume is the vent to the carb. Can anybody verify where the fuel lines are supposed to go?

 

[achris]

One for fuel in, one for fuel out, and one for 'diaphragm rupture' which goes to a fitting on the carb. The idea is that if the pump diaphragm ruptures it dumps a ton of fuel directly down the carb throttle barrel and stalls out the engine.

 

[JimboFisher]

That makes more sense. there is a ported vacuum tube with a plastic cap on it but no port on the Flame Arrestor. Thanks!

 

[achris]

That makes more sense. there is a ported vacuum tube with a plastic cap on it but no port on the Flame Arrestor. Thanks!

Not the flame arrestor, the carb!

 

[JimboFisher]

I know. There isn’t even a port on the arrestor but there is an extra ported vacuum on the carb that is plugged off with a vacuum cap that i was planning on using. Ported vacuum ok? Or manifold vacuum?

 

[Bondo]

Ayuh,..... Should be no vacuum, just a port to dump excess gas straight down the throat of the carb,.....

Yer carb with a vacuum port, makes me wonder whether it's a Marine rated carb,.....

 

[Scott Danforth]

my OMG 3.0 had the tell-tale nipple on the spark arrestor.

@JimboFisher post a pic of your carb

 

[Alumarine]

As long as the "vacuum port" is above the butterflies should it not be ok for the fuel pump vent?

 

[achris]

As long as the "vacuum port" is above the butterflies should it not be ok for the fuel pump vent?

No.

 

[Alumarine]

No.

So this is no good?

 

[JimboFisher]

As long as the "vacuum port" is above the butterflies should it not be ok for the fuel pump vent?

The vacuum port is just below the arrestor base it is above the choke butterfly so it’s going to work just fine. Thought it was ported vacuum but it’s not. Atmospheric pressure only. Thanks folks for the help.yep that’s the port I’m using

 

[achris]

So this is no good?

Please don't hijack someone else's thread. If you have a question, start your own thread.

Chris....
iboats mod team