Water Separator Questions

apace2

Cadet
Joined
Apr 3, 2011
Messages
12
My engine is a 1985 30 hp Johnson. I have been running an inline fuel filter but was thinking I should maybe put a water separator on instead. I'm not really familiar with what exactly water in the fuel lines does. Do people run water separators on small outboards? Can anyone recommend a good brand/type of water separator? Thanks.
 

fhhuber

Lieutenant
Joined
Jun 19, 2014
Messages
1,365
Water in the fuel would kill the engine. You clear the water and it works again.
With the common 10% alcohol in gasoline now though the water will generally be mixed in rather than separating to the bottom of the tank. It would take a LOT of water to give issues. its only when it separates that it causes problems.

There used to be water injection systems sold for cars as an attempt to improve gas mileage. They can actually work if you get the water to spray into the carb right. They can also increase pressure in the combustion chamber to the point of destroying the engine if you find the "perfect" ratio of water to fuel.

Also a trick for cleaning the combustion chamber and plugs without using a wrench is to trickle water down the carb. (detergent motor oil burning in a car will accumulate deposits that need to be cleaned out regularly) Applies mostly to cars that are so bad its "fill the oil and check the gas"

A filter will generally be far more important than a water separator.
 

mattsmall1972

Petty Officer 1st Class
Joined
May 14, 2006
Messages
238
I have a 1985 Evinrude 35 and I put a water/fuel separator on it after my buddy killed his Force 120 with water in the gas. I have a small 6 gallon tank and likely won't ever encounter the amount of water he has in his underdeck tank, but it certainly cannot hurt. Run both a separator and the fuel filter in series - it will help to keep the gas safer for your engine.
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
You can buy fuel filters/water separators all in one. Check Racor.com.
 

Fed

Commander
Joined
Apr 1, 2010
Messages
2,457
I've never run a separator but I don't put water in my gas tanks either.
 

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
If you regularly run the engine and always keep new fuel in the tank, you probably don't need a fuel/water separator. The person that takes 8 months to consume a tank of 6 gallons of fuel should consider a water separator. The longer ethanol fuel sits, the more chance it has to accumulate water/moisture.
 

dingbat

Supreme Mariner
Joined
Nov 20, 2001
Messages
17,174
4 stroke don't worry about. 2 strokes have very little tolerance for water in the fuel. Water has granaded more than a couple of two strokes
 

Gold Eagle Co

iboats Partner
Joined
Apr 20, 2015
Messages
85
Hi everyone,

We work for Gold Eagle Co (makers of STA-BIL?) and are here to help clear up some confusion. Water in ethanol blended gas can certainly cause some problems. Really the best way to keep water out of the fuel is to keep the fuel system as full as possible. This will significantly cut down on the space for condensation to form. In addition to the potential for phase separation, water in the fuel system can also cause a great deal of rust & corrosion to any metal components of the system.

Please let us know if you have any questions.

Have a great day!
 
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