What size Fuel Water Separator? 1998 Mercury Force 120 HP.

[L3af]

Hi Friends,

I have a 1998 Mercury Force 120 HP.

I believe the fuel lines are 3/8, the old fuel water separator that was on the boat appears to be 1/4 inch.

Is this the correct size?

 

[jerryjerry05]

Just change the fittings to what ever size the hose is.
The better or more expensive the filter the better the results.
I ran a Racor with the clear bowl and water drain on the bottom.
That way you can see any water build up.

 

[Chris1956]

Any of the screw on oil filter like water separators will work. You want at least a 5/16" fuel line fitting, but 3/8" is best.

The Racor's with the clear bowl are nice, but are more expensive, have two gaskets that can leak, and will deteriorate is left in the sun. I use the cheaper metal canisters and change them every year. You can also dump them into a clear container and see if there is any water in them.

If you constantly need to drain water from the Racor filter, you need to get the water out of your fuel tank, before it hits the engine. Carbs do not like to burn water but will get over it. Water ruins injectors.

 

[L3af]

Just change the fittings to what ever size the hose is.
The better or more expensive the filter the better the results.
I ran a Racor with the clear bowl and water drain on the bottom.
That way you can see any water build up.

I'm actually really confused.

I keep seeing things like:

Fuel Line Compatibility: 3/8"
NPT Fitting: 1/4"

Does a 1/4 NPT fit a 3/8 hose?

 

[L3af]

Any of the screw on oil filter like water separators will work. You want at least a 5/16" fuel line fitting, but 3/8" is best.

The Racor's with the clear bowl are nice, but are more expensive, have two gaskets that can leak, and will deteriorate is left in the sun. I use the cheaper metal canisters and change them every year. You can also dump them into a clear container and see if there is any water in them.

If you constantly need to drain water from the Racor filter, you need to get the water out of your fuel tank, before it hits the engine. Carbs do not like to burn water but will get over it. Water ruins injectors.

Is it safe to put the Racor style plastic bowl fuel filters in a hatch/compartment with the battery?

 

[Scott Danforth]

I'm actually really confused.

I keep seeing things like:

Fuel Line Compatibility: 3/8"
NPT Fitting: 1/4"

Does a 1/4 NPT fit a 3/8 hose?

Yes.

1/4 NPT is about 0.54" in diameter with almost a 3/8" ID

 

[jerryjerry05]

Is it safe to put the Racor style plastic bowl fuel filters in a hatch/compartment with the battery?

Yes
I used the Racor for over 30 years and never had a problem.
The metal canisters are subject to rust and corrosion and they can collapse when trying to remove them. Salt water destroys them and the mount for the filter. The Racor is more expensive but you get what you pay for.

 

[Chris1956]

Gee, the metal water separator canisters do not rust in my speedboat, where everything else does. I have never had one collapse.

Install them hand tight only. Using a tool on them scratches the paint, and then they can rust. Usually you can get them off by hand, but a std oil filter wrench removes the stubborn ones.

Racor's can have plastic parts. If something slides or rolls into them, they can crack.

 

[Scott Danforth]

I have never had a racor that didnt leak. either personally or professionally.

since I replace the fuel filter every year, the 10 micron metal canister is good enough, even on my salt water boat.

 

[L3af]

Thanks Guys, it seems I'm just over thinking.

 

[rhedayi]

I used the atwood separator kit. The filters are cheap too. You need 3/8 inch npt fittings with 3/8 barbed end. Like these https://www.ebay.com/itm/1262185866...-QekUlWSMy&var=&widget_ver=artemis&media=COPY