Fuel/Water Separator

inPursuit

Cadet
Joined
Mar 10, 2009
Messages
16
I would like to replace my fuel/water separator and would like to know what the best type to use is? 10 Micron, 30 Micron, etc... ???
 

dingbat

Supreme Mariner
Joined
Nov 20, 2001
Messages
15,417
Re: Fuel/Water Separator

E-10 fuel = 10 micron filter with drain?.preferably ;)
 

Woodnaut

Chief Petty Officer
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Jul 4, 2007
Messages
634
Re: Fuel/Water Separator

I have a late model fuel injected outboard. I believe the manufacturer's recommendation is a 10 micron. If you do a search on this forum you will find more information on the preferred brands and styles. A lot of guys prefer the visible bowl type. BUT, any reputable filter has got to be better than no filter.
 

bowman316

Lieutenant Commander
Joined
Oct 21, 2008
Messages
1,822
Re: Fuel/Water Separator

are fuel water seperators intended only for larger boats?
I have a 16 ft 70 hp outboard, and I heard i should not waste the money on it for me.
 

inPursuit

Cadet
Joined
Mar 10, 2009
Messages
16
Re: Fuel/Water Separator

Thanks for your responses. I guess I will try the 10 Micron because it seems to very difficult to find fuel without the 10% ethanol. Thanks again
 

inPursuit

Cadet
Joined
Mar 10, 2009
Messages
16
Re: Fuel/Water Separator

bowman316,
I have an 18'6" CC with 150 Yamaha and have always used the fuel/water separator and find it to be helpful. I would guess I need to drain the water from it a couple of times a year. Apparently the best style to use is a 10 Micron filter with "bowl" on the bottom that will allow you to drain the separated water.
 

Woodnaut

Chief Petty Officer
Joined
Jul 4, 2007
Messages
634
Re: Fuel/Water Separator

Bowman, I use the same filter housing with my fuel injected 90 HP Yamaha as I did when I had a 70 HP merc 2-stroke on the boat. The only difference is I switched the filter element from a 30 micron to a 10 micron with I went from carbs to fuel injection. These filters are worth it. It will keep the fuel cleaner and the engine happier. Personally, I'd have one no matter what size of engine it was.
 

ebry710

Ensign
Joined
Jan 29, 2008
Messages
981
Re: Fuel/Water Separator

are fuel water seperators intended only for larger boats?
I have a 16 ft 70 hp outboard, and I heard i should not waste the money on it for me.

My mechanic changed my gas/water separator and pulled 12 ounces of water from my 40 gallon tank. It is not the size of the engine, but the turn around time on fuel use, how long the fuel sits and the stabilizers in the fuel that determines water in the tank.
 

dingbat

Supreme Mariner
Joined
Nov 20, 2001
Messages
15,417
Re: Fuel/Water Separator

It is not the size of the engine, but the turn around time on fuel use, how long the fuel sits and the stabilizers in the fuel that determines water in the tank.


99% of all water in tank is either introduced into the system via a vent or from the tanks of the service station.

You can leave a gallon of untreated gas open in your garage for 6 months and the only thing that will haapen is that you will have less gas than you began with.
 

ebry710

Ensign
Joined
Jan 29, 2008
Messages
981
Re: Fuel/Water Separator

99% of all water in tank is either introduced into the system via a vent or from the tanks of the service station.

You can leave a gallon of untreated gas open in your garage for 6 months and the only thing that will haapen is that you will have less gas than you began with.

One of the nature bi-products of the break down of a gasoline/oxygen combination is water. Where do you suppose the water in the service station comes from? It is a closed system.
 

dingbat

Supreme Mariner
Joined
Nov 20, 2001
Messages
15,417
Re: Fuel/Water Separator

One of the nature bi-products of the break down of a gasoline/oxygen combination is water. Where do you suppose the water in the service station comes from? It is a closed system.

You can not make water at the atomic level by combining oxygen and gasoline. The combination of gas and oxygen cause the fuel to oxidize which in turn and forms gum and varnish.

The water is introduced into the storage tanks via thermal cycling.
Gasolines ability to "absorb" water is directly proportional to it?s temperature. The greater the fuel temperature the greater the amount of moisture the fuel can hold in suspension.

Putting ?warm? gas from a truck into a ?colder? under ground storage tank will cause the fuel to shed the extra moisture which will settle to the bottom of the storage tank. You also have point source introduction of water into the tanks as noted below in an excerpt from a fuel supplier.


Water can enter a tank through several means. Loose fill caps, leaky fittings and faulty gaskets are all entry points for water. Water can accumulate around the fill gauge manhole or in the secondary containment submersible pump pit. A leak in the tank or the lines will allow moisture to enter the tank; this is especially true of underground storage tanks. Every time the tank is open, there is a potential for water to enter.
 
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