Mercruiser 470 Fuel Filter

[saltydogjeff]

I have been trying to get my engine running for a little while. I am at the point where the fuel is necessary to start the motor. I have replaced the carburetor, and am in the middle of bending new pipe from the fuel filter to the carburetor. My first attempt at bending the pipe didn't turn up too bad, but I noticed there was no fuel going from the bottom of the fuel filter through the plastic hose to the side of the carburetor. I then noticed there was fuel in the fuel line from the fuel filter. So my question is... what happens if there isn't any fuel in the plastic line that is on the bottom of the fuel filter? Also, the fuel filter is connected to the block of my engine, and there looks to be a gasket there. What happens when I remove the filter from my engine? Would I open up an oil port where I would then have to be quick with my hands or is this just for vibrational, connection purposes? I want to take the fuel filter off to clear up any blockage, because I noticed a ton of green gook in the fittings towards each outlet. Please let me know what is recommended in this situation.

 

[alldodge]

Re: Mercruiser 470 Fuel Filter

I have been trying to get my engine running for a little while. I am at the point where the fuel is necessary to start the motor. I have replaced the carburetor, and am in the middle of bending new pipe from the fuel filter to the carburetor. My first attempt at bending the pipe didn't turn up too bad, but I noticed there was (1) no fuel going from the bottom of the fuel filter through the plastic hose to the side of the carburetor. I then noticed there was fuel in the fuel line from the fuel filter. So my question is... (2) what happens if there isn't any fuel in the plastic line that is on the bottom of the fuel filter? Also, the fuel filter is connected to the block of my engine, and there looks to be a gasket there. (3) What happens when I remove the filter from my engine? Would I open up an oil port where I would then have to be quick with my hands or is this just for vibrational, connection purposes? I want to take the fuel filter off to clear up any blockage, because I noticed a (4) ton of green gook in the fittings towards each outlet. Please let me know what is recommended in this situation.

(1) This line is between the primary and secondary diaphrams and is there for safety. All marine fuel pumps are dual diaphrams so when the first one breaks it dumps fuel into the carb instead of the bildge. By doing this the fire and explosion hazard is midagated and it lets you know its time to replace the pump.

(2) Same reason as above, which means your fuel pump is in good order.

(3) Nothing, you may loos a little fuel but the pump will refill. Folks usually refill the new one with fresh gas before reinsatll to make it easier to start. Otherwise the pump will need to refill the filter before it will run properly.

(4) This is not an issue, brass fittings when exposed to air and mosture will turn green. Just wire brush it off and repaint.

 

[Bt Doctur]

Re: Mercruiser 470 Fuel Filter

What you have is a fuel pump that contains a fuel filter.liquid in the small plastic line means the fuel pump has failed and needs replacement.

 

[Bt Doctur]

Re: Mercruiser 470 Fuel Filter

 

[saltydogjeff]

Re: Mercruiser 470 Fuel Filter

Another question. What happens when I remove the fuel pump from the block? Do I need to drain the oil before doing this?

 

[Bt Doctur]

Re: Mercruiser 470 Fuel Filter

no, no oil will just run out of the block. all the oil is contained in the pan.

 

[akatom2u]

Re: Mercruiser 470 Fuel Filter

What you have is a fuel pump that contains a fuel filter.liquid in the small plastic line means the fuel pump has failed and needs replacement.

Awesome info on carb, thanks a lot for your sharing.