what is the 3/16 hose off the bottom of my fuel pump mercruiser 1979 470.

[sparky895]

Anybody know if this hose is a vent or preasure releif and where should the other end go? Mine is just stubbed up and ends in open air by the valve cover.

Thanks everyone,

Greg

 

[boatnut74]

Re: what is the 3/16 hose off the bottom of my fuel pump mercruiser 1979 470.

That hose should connect back to the carb. It's there for if the diaphram on the fuel pump goes out it will dump the fuel into the carb instead of into the bilge.

 

[sparky895]

Re: what is the 3/16 hose off the bottom of my fuel pump mercruiser 1979 470.

That hose should connect back to the carb. It's there for if the diaphram on the fuel pump goes out it will dump the fuel into the carb instead of into the bilge.

Thanks, do you know where it goes in at? I don't think i have any open barbs with nothing on them right now. This work was done by the previous owner so i am trying to straighten out all these little details.

Thanks again,

Greg

 

[boatnut74]

Re: what is the 3/16 hose off the bottom of my fuel pump mercruiser 1979 470.

It's usually towards the top of the carb. Atleast all the ones I have seen are there.

 

[NetDoc]

Re: what is the 3/16 hose off the bottom of my fuel pump mercruiser 1979 470.

Anybody know if this hose is a vent or preasure releif and where should the other end go? Mine is just stubbed up and ends in open air by the valve cover.

As has been stated, the vent is keep fuel out of the crankcase if/when the diaphragm ruptures and it goes to the outer bowl vent of your carburetor. Only marine versions of both carbs and pumps have these vents, so you might have the wrong carb. My Mercruiser was converted to an electric pump and the previous owner just left the tube dangling from the carburetor. It was strategically placed over the starter and he was perplexed why he went through starters. Its capped off now. Fuel and fuel vapors are dangerous. Please use extreme care when working with these systems.

 

[sparky895]

Re: what is the 3/16 hose off the bottom of my fuel pump mercruiser 1979 470.

As has been stated, the vent is keep fuel out of the crankcase if/when the diaphragm ruptures and it goes to the outer bowl vent of your carburetor. Only marine versions of both carbs and pumps have these vents, so you might have the wrong carb. My Mercruiser was converted to an electric pump and the previous owner just left the tube dangling from the carburetor. It was strategically placed over the starter and he was perplexed why he went through starters. Its capped off now. Fuel and fuel vapors are dangerous. Please use extreme care when working with these systems.

Thanks for the advise, the reason for the post is to get everything back together so it is safe.
The carb has a sierra tag on it so I am asuming it is not stock. I don't see a port for the hose, what would hapen if I tied it into the tank vent line, would that be an option?

Thanks

Greg

 

[NetDoc]

Re: what is the 3/16 hose off the bottom of my fuel pump mercruiser 1979 470.

what would hapen if I tied it into the tank vent line, would that be an option?

I am not sure what would happen, but it might possibly dump raw fuel overboard which is not acceptable. As expensive as they are, if it were my boat, I would find a carburetor appropriate for the application or at a minimum, switch to an electric pump.

 

[proshadetree]

Re: what is the 3/16 hose off the bottom of my fuel pump mercruiser 1979 470.

Pics speak a thousand words. You can convert a automotive carb to marine

 

[Bondo]

Re: what is the 3/16 hose off the bottom of my fuel pump mercruiser 1979 470.

I don't see a port for the hose,

Ayuh,... Look on the bottom of the flame arrester...