Fuel Filter and Separator add-ons

Nehalennia

Nehalennia

Well-Known Member
Aug 22, 2007
10,006
Marysville, WA
Boat Info
2001 310DA twin 350 MAGs, Westerbeke 4.5KW
Engines
Twin 350 MAG V-drives
I was thinking of adding a Water separating Fuel Filter.
Is this considered enough as a fuel filter or is there an additional fuel filter that also should be installed inline?

Water Separating Fuel Filter Kit SKU: 802893A 4
image.php
 
5.7 can flow about 20 to 25 GPH depending on HP rating. Sounds too small for your application.
 
Thanks Guys. I'll look into the proper application further.
 
fc3 said:
5.7 can flow about 20 to 25 GPH depending on HP rating. Sounds too small for your application.
Click to expand...

Was flow rate even specified in the specs? I couldn't find it?

Ever other site I searched for that filter specified 'Fits all MCM/MIE models, except 1992 MCM 4.3L Gen II engines equipped with an in-line fuel filter.'

I stand by my statement that the filter kit should work fine in your application.

Doug
 
ImpulseIII said:
And what is Todd supposed to do if you are wrong?
Click to expand...

I didn't find any specs online either, but I'll be calling Merc to verify if it would be recommended. I didn't consider this kit to be as restrictive as FW and Frank C warned but that's why I ask here first. Might as well put holes in a theory or generate the questions to ask before atttempting such a mod.

Thanks again guys.
 
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There already should be a fuel filter and water separator on the engine. Installing a second may decrease fuel flow or lower the pressure between the fuel pump and fuel filter to a point below the vapor pressure of the fuel, resulting in vapor lock.
 
Perhaps a dumb question... But isn't the fuel pump for a fuel injected engine right after the tank, before the filters? In an automobile application, it's actually in the tank. When I last looked at my 240, it looked like it was the first thing out of the tank (I really didn't look at it too closely, nothing is wrong with it!). If a restriction is placed post pump, he'll end up with starvation at the rails, loss of additional power... and since this is an open loop engine, probably a lean condition with some extra heat.

But I may be wrong...
 
Jim240 said:
Perhaps a dumb question... But isn't the fuel pump for a fuel injected engine right after the tank, before the filters? In an automobile application, it's actually in the tank. When I last looked at my 240, it looked like it was the first thing out of the tank (I really didn't look at it too closely, nothing is wrong with it!). If a restriction is placed post pump, he'll end up with starvation at the rails, loss of additional power... and since this is an open loop engine, probably a lean condition with some extra heat.

But I may be wrong...
Click to expand...

Every EFI marine engines I've seen has the fuel pump attached somewhere on the engine and usually downstream of the fuel filter. It's safer since the fuel filter isn't pressurized to 40 or so PSI. Only the fuel rail and a small section of plumbing from the pump to the rail is pressurized.

Best regards,
Frank
 
fc3 said:
Every EFI marine engines I've seen has the fuel pump attached somewhere on the engine and usually downstream of the fuel filter. It's safer since the fuel filter isn't pressurized to 40 or so PSI. Only the fuel rail and a small section of plumbing from the pump to the rail is pressurized.

Best regards,
Frank
Click to expand...

Plus EFI pumps don't tolerate dirt being pumped through them.

Doug
 
douglee25 said:
Plus EFI pumps don't tolerate dirt being pumped through them.

Doug
Click to expand...

Automotive EFI pumps are located upstream of the fuel filter. They must tolerate some dirt.

Which reminds me. I need to change the fuel filter on the Navi. Hate to think how many thousands of gallons have flowed though that filter since the last change.

Best regards,
Frank
 
fc3 said:
Automotive EFI pumps are located upstream of the fuel filter. They must tolerate some dirt.

Which reminds me. I need to change the fuel filter on the Navi. Hate to think how many thousands of gallons have flowed though that filter since the last change.

Best regards,
Frank
Click to expand...

There's a filter sock of some type in the tank on your setup. Not every vehicle has a filter after the pump either. In fact, my old vehicle had the filter prior to the EFI fuel pump.

Doug
 
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Interesting... learn something new everyday... Thanks!

BTW, they still have a return line to the tank to circulate the fuel around the rail and not let it sit and get hot?
 
And this is my concern about the flow rates..............

Some fuel injected engine do have return lines and if Todd's is one of those, then he need significantly more filter flow capacity than the engine burns.
 
Todd, are you saying that you don't currently have one on your boat? Or are you trying to add to your system. The reason I ask is I believe you already have one of the very units your talking about adding. Bottom left of the engine, it's got some kind of cover around it. I might be wrong but it sure looks like it when I look at the clean bildge pics you posted awhile back.
 
Woody said:
Todd, are you saying that you don't currently have one on your boat? Or are you trying to add to your system. The reason I ask is I believe you already have one of the very units your talking about adding. Bottom left of the engine, it's got some kind of cover around it. I might be wrong but it sure looks like it when I look at the clean bildge pics you posted awhile back.
Click to expand...

Well that's what I need to inspect further at the boat. I do have what I believe is a fuel cooler, but I don't see a spin on fuel filter/separator in line from the tank to the Engine.

My thought was that it would possibly be a good idea since my boat will sit longer between trips this time of year and separating the water out may be a good idea.

So I thought I'd ask for the advice here and was glad to see the "Warning" posts that it may not be a good idea or at least prompting me to ask more questions than eroneously buying one and screwing it on, simply because it fits.

Here's a picture of the engine
Engine1.jpg

Look at the bottom left. I believe that is the fuel cooler.
 
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