To fuel filter or not. 3.0

[Mercperk]

Seems some documents state not to put a fuel water separator filter on a 3.0l mercruiser, is that correct?
Do they really just want you to rely on the mechanical fuel pump filter?
Is it just that the mechanical fuel pump is not robust enough to draw through it?

I'd hate to starve the engine of fuel
Thanks in advance!

 

[Alumarine]

What documents are these?
I've had them on 3.0's for years and they work fine.

 

[ThomW]

I agree with Alumarine....both my previous 3.0's had them and there were never any issues. What reason do these documents state as their rationale?

 

[Scott Danforth]

the reason the 3.0 doesnt have a good fuel/water filter is that its the base engine for most boats and they had to cut costs to get the boat price down to a price point.

the 3.0 needs a filter just like any other motor

the fuel pump on the 3.0 is nearly identical to the fuel pump the small blocks and big blocks (just a different actuator arm shape). you wont ever starve it for fuel by putting the proper filter on it.

 

[achris]

There isn't an engine out there that should be run without a fuel filter.

 

[Bondo]

Ayuh,..... Not only does a canister filter help keep water outa the carb, but it's a great diagnostic tool for runability problems,....

 

[havoc_squad]

Seems some documents state not to put a fuel water separator filter on a 3.0l mercruiser, is that correct?
Do they really just want you to rely on the mechanical fuel pump filter?
Is it just that the mechanical fuel pump is not robust enough to draw through it?

I'd hate to starve the engine of fuel
Thanks in advance!

That's a load of crap about saying do not put water separating filter on a 3.0L engine.

As long as the fuel filter & filter mounting assembly supports the gallons per hour output needed by the motor, there is no reason not to have one installed.

This is especially important to have installed if you run E10 gasoline instead of no Ethanol gas because E10 gas will retain water over time and mess crap up in your fuel system even if you use a good fuel stablizer.

Make sure you use USCG A15 rated inboard fuel hose for installing it.

 

[nola mike]

This is especially important to have installed if you run E10 gasoline instead of no Ethanol gas because E10 gas will retain water over time and mess crap up in your fuel system even if you use a good fuel stablizer.

I mean, this part isn't true, but that's a different thread...

 

[Lou C]

Most canister filters are rated at like 60 gph a 3.0 is going to use like at most 10-15 gph I’d think.

 

[Mercperk]

Sorry I don't know what is wrong with me. I should have been more specific.
These are just the general repower statements, regardless enough for me to ask y'all.
Here's a picture of the quicksilver repower literature that came with the crate motor.
#2 on the bottom of the page

 

[Mercperk]

Sorry I don't know what is wrong with me. I should have been more specific.
These are just the general repower statements, regardless enough for me to ask y'all.
Here's a picture of the quicksilver repower literature that came with the crate motor.
#2 on the bottom of the page

Says
2. Should I as a fine-micron filter to the system to prevent debris from entering the engine?
No. .....
Talks about fuel starvation

 

[Mercperk]

the reason the 3.0 doesnt have a good fuel/water filter is that its the base engine for most boats and they had to cut costs to get the boat price down to a price point.

the 3.0 needs a filter just like any other motor

the fuel pump on the 3.0 is nearly identical to the fuel pump the small blocks and big blocks (just a different actuator arm shape). you wont ever starve it for fuel by putting the proper filter on it.

Well I mean a different shape will give a different pump right?

 

[Mercperk]

There isn't an engine out there that should be run without a fuel filter.

Depends on your definition of a filter I suppose...

 

[Mercperk]

Ayuh,..... Not only does a canister filter help keep water outa the carb, but it's a great diagnostic tool for runability problems,....

Could possibly be the "runability problem" itself too.....it definitely happens with smaller horsepower engines or over eager owners too

 

[Mercperk]

That's a load of crap about saying do not put water separating filter on a 3.0L engine.

As long as the fuel filter & filter mounting assembly supports the gallons per hour output needed by the motor, there is no reason not to have one installed.

This is especially important to have installed if you run E10 gasoline instead of no Ethanol gas because E10 gas will retain water over time and mess crap up in your fuel system even if you use a good fuel stablizer.

Make sure you use USCG A15 rated inboard fuel hose for installing it.

Alcohol gets rid of water in your gas doesn't it?

 

[Mercperk]

Every other crate engine comes with water separator. Why is that?

 

[Lou C]

The standard 20 micron filter canister is not a considered a fine micron filter. They are referring to something like a 2 micron filter. Not a standard 20 micron for carbed engines.

 

[nola mike]

Alcohol gets rid of water in your gas doesn't it?

Yes, until it gets saturated

Every other crate engine comes with water separator. Why is that?

Most/all newer Merc engines came with the screw on filter I believe.

I think we're done with this ... Either use it or don't. There has never been a post here --ever-- where someone has added a filter and had problems. Do what you will with that.

 

[Mercperk]

My plan was for the big micron filter but I would like to make sure this is kosher as every used 3.0l I looked at that was visible hooked to a filter did have more noticeable vertical scoring on the cylinder walls, almost as if it was fuel starved. Figured I'd ask all y'all. Perhaps I read too much forum who knows these things...
Another filter question; to ensure the least drop in fuel flow the correct installation is at what level when compared to tank? I thought there was some spec.....

 

[Lou C]

If that’s the case the cause was probably not changing the oil. Look at the spec on some of those filters. A Racor flows 90 gallons per hour!