water in fuel tank????

[jahoward1]

Hey Bob,

Question: I have a 1997 200 Osprey cc.  The 115hp Johnson was rebuilt last year and it runs great.  I have no complaints other that hard starting sometimes but that usually after she's sat a while.  Anyway, when I picked the boat up from the mechanic, he explained to me that there was alot of water in the gas tank and they had emptied as much of the water as they could.  He also advised me that I needed to continually check and empty my water/fuel seperator.  My question is, how could water get into the fuel tank in the 1st place?  I've been on the boat maybe 5 times this season and admittedly haven't checked the seperator yet.  

And staying with fuel, I also have a fuel guage I can't trust.  The guy who sold me the boat gave me a receipt that demostrated that he had fixed the fuel guage and the tach but I never know if the fuel guage is correct or not.

Finally, my boat leans slightly to the starboard while underway.  Could that be caused by water in the tank?  I'm very new to boating and not much a mechanic but I am learning more each day.  And, oh yeah...I love this boat.  Sorry this post is so long but thanks in advance.

James H :afro:

[RickK]

Water in fuel = ethanol  :cry:

[MarshMarlowe196]

Water in fuel = ethanol  :cry:

???

Water finds its way into a lot of things you would never think it would (like gas tanks, and oil tanks for oil injected outboards).  It could have gotten in there through a loose/open fill cap, the vent hose, through an unsealed sending unit plate on the top of the tank, or other several ways that only God really knows.  That's why its always a good idea to keep an inline fuel/water separator.  

Water got into my tank when I cleaned it out with water and degreaser.  It was impossible to get all the water out after it got in, so your mechanic is probably telling you the truth on that.  I siphoned out the tank as best I could and filled a few 10 gallon gas tanks up with what I siphoned out.  Since water is more dense than gas, it separates to the bottom of whatever container its in.  So you have fuel on top, and water on bottom, almost perfectly separated from each other.  I put the gas I could salvage back in the fuel tank, but you'll never really get all the water out.  Since your fuel pickup in your tank is on the bottom of the tank, the water should be picked up first.  If it was picking up a lot of water, it would be extremely difficult if not impossible to keep your engine running.  So, since your engine is running, that probably means there's not a whole lot of water left in the tank.  :)

All you have to do with that water filter is unscrew it, dump it all out, and screw it back on.  That gets rid of the water in the canister.  They also make fuel/water separators with a purge valve that you can purge the water off with, without removing the filter.

You're not the only one who can't trust their fuel gauge-  If you have the typical fuel gauge setup with a tank mounted sending unit, it usually wont give you an accurate reading of how much fuel you have.  The reason for that is the sending unit is really just a variable ground, and the float makes the ground stronger or weaker, depending on where it's floating on the sending unit.  The strength of the ground is being shown on your fuel gauge.  A lot of things can mess with the ground, other than the sending unit,  and give you a bad reading, but it should more or less give you an educated guess as to how much fuel you have.

Your boat leaning to starboard would not be caused by water in the tank.  Do you have batteries in the stern of your boat?  Are they on the starboard side?  I find that these boats will lean to one side or the other with the smallest imbalance of weight.  Mine leans to port, because of the prop spinning clockwise and causing the boat to lean.

[RickK]

Ok, some kind of weird thing might have happened that deluged his tank in water.  If it wasn't the ethanol that soaked up all the moisture this time - it will be in the future.  Make sure you get a water separator - note to self, I need to do the same for both boats  :cry:

[lynnstrick01]

Ethanol is an alcohol,  which is now in almost every gasoline you purchase is a solvent, degreaser, cleanser, antifreeze an yes, Water absorber.   Ethanol fuels absorb up to 50 percent more water than non alcohol gasolines.  This does not present a problem in our cars because with normal driving you would use up the gasoline before it had an opportunity to absorb enough water to cause damage.  Boats will typically sit a lot longer between use, allowing condensation to build up, the ethenol then absorbs the condensation and pulls that water into your motor causing havoc with carborators, spark plugs and more.   There is a wonderful product called  MARINE FORMULA STA-BIL ethanol treatment.(check out the web site) http://www.goldeagle.com/brands/stabil/default.aspx  It can be purchased at most marine stores, it comes in a small bottle that is clear and is the size and shape of the old STP gas treatment bottles, the product is Blue in color. This is a great product that will prevent water build up in your tank if you use it BEFORE you have a problem,  If you use it after you already have water in your tank you could be asking for more trouble, it will have a tendency to CLEAN your tank, it does help dry the water but it can also loosen sludge and "varnish" that has accumulated in your tank causing even more problems.

If you already have water in your tank suggest you, empty the gas into another clean container that is easier to work with and try to seperate the water from the gas.  meanwhile you will need to pull your tanks and clean and dry them thoroughly, then when you re-fill add the gasoline along with the reccommended dosage of Sta-bil to prevent future water build up.

Hope you find this helpful.

[MarshMarlowe196]

Ethanol is an alcohol,  which is now in almost every gasoline you purchase is a solvent, degreaser, cleanser, antifreeze an yes, Water absorber.   Ethanol fuels absorb up to 50 percent more water than non alcohol gasolines.  This does not present a problem in our cars because with normal driving you would use up the gasoline before it had an opportunity to absorb enough water to cause damage.  Boats will typically sit a lot longer between use, allowing condensation to build up, the ethenol then absorbs the condensation and pulls that water into your motor causing havoc with carborators, spark plugs and more.   There is a wonderful product called  MARINE FORMULA STA-BIL ethanol treatment.(check out the web site) http://www.goldeagle.com/brands/stabil/default.aspx  It can be purchased at most marine stores, it comes in a small bottle that is clear and is the size and shape of the old STP gas treatment bottles, the product is Blue in color. This is a great product that will prevent water build up in your tank if you use it BEFORE you have a problem,  If you use it after you already have water in your tank you could be asking for more trouble, it will have a tendency to CLEAN your tank, it does help dry the water but it can also loosen sludge and "varnish" that has accumulated in your tank causing even more problems.

If you already have water in your tank suggest you, empty the gas into another clean container that is easier to work with and try to seperate the water from the gas.  meanwhile you will need to pull your tanks and clean and dry them thoroughly, then when you re-fill add the gasoline along with the reccommended dosage of Sta-bil to prevent future water build up.

Hope you find this helpful.

Though it is a good idea to add Stabil to your tank if you plan on storing it over a long period of time (several months), adding Stabil to a tank with moisture already in the fuel will not solve a problem caused by Ethanol in the fuel absorbing moisture.  Stabil also does not prevent moisture buildup, it actually doesn't prevent the Ethanol from absorbing it either.  The truth is- there's been ethanol in gas since the 70's, just not as much as there is now, and although E fuel absorbs 10x as much moisture, it will still run safely through your engine.  It's really not that big of a deal.  Products like Stabil are good at preventing the buildup of sediments in a fuel tank over a long period of time that would normally go unchecked without it.  Ethanol, being a solvent, breaks down these sediments in your fuel tank in a shorter period of time (because there's more ethanol now), and these sediments end up wherever the fuel flows, causing clogged fuel lines/filters/carburetors/ etc., hence so many people screaming about ethanol fuel.  Since we have more ethanol in our fuel now, Stabil has come out with a more powerful (and more expensive) product (Stabil Marine) to combat the added solvents in the fuel (ethanol).

Fact is-  if Ethanol had absorbed enough moisture in your fuel, the fuel would experience "phase separation" and your engine simply would not run at that point.  The good news is that Ethanol fuel would have to sit in your tank for a very long period of time (several months) with enough moisture present to become that saturated (at that point the only fix would be to drain the tank completely and refill with fresh fuel).

SO-  since your engine is apparently running, and you've used the boat an average amount of times this season, I don't think ethanol is something you should worry about.  Empty that water separator, screw it back on, AND USE YOUR BOAT!!  That will keep fresh gas in the tank and any pesky ethanol problems at bay.

Also, when it comes to storing your boat, the best way to prevent moisture buildup (especially with all this corny gas) is to fill your tank 95% full (to allow for expansion), and to prevent as much moisture/condensation buildup in your tank as possible.  And yes, add Stabil.  

[Wayne'sWorld]

As to the fuel guage... if you're not getting an accurate read, and if you are going to empty the tank, feed the old gas to your lawnmower then put in a known amount at the pump.  Watch the guage to see how it reads on the trailer (assuming you trailer) then look at the guage when the boat is in the water at relative calm.  You may get two different readings.

Ex:  I put 32 gallons of fuel into a 74 gallon tank.  Took the boat to the ramp and checked the guage while sitting on the water.  The guage didn't read 1/2 full but who cares?  I have a known quantity of fuel and I know where that reads on the guage now.  Each time I go out I top up the tank.  If I'm on the water and the guage is moving toward that 32 gallon mark, I know where I need to be in relation to the ramp and I won't concern myself with being caught short.  Probably can't get 74 gallons of fuel in a 74 gallon tank anyway!

Have fun!

[lynnstrick01]

and although E fuel absorbs 10x as much moisture, it will still run safely through your engine. It's really not that big of a deal.

OK, I am certainly not arguing with you, but I saw it with my own eyes in my marine mechanics shop, he had 2 quart jars with typical ethanol gasoline, one with Stabil- and one without, the water in the one without Stabil was UNREAL and the one with Sta-bil  had virtually no water at all.   I am far from a mechanic but it sure seems like all that water couldnt possibly be good for any engine.

[uc4me]

Another product to also consider is K100 (http://www.k100fueltreatment.com/).  The E10 problem (racket) is quite the problem here in the northeast and this product works very well.  It actually encapsulates the water molecule and acts as a lubricator.  Not all treatments are the same.  Another that i use is Star Brite's Star-Tron Fuel Treatment (http://mystarbrite.com/startron/) but prefer the K100 overall.

Also, every state is different regarding the content/makup of the gasoline sold (http://www.mobil.com/USA-English/GFM/Fi ... ne_Map.pdf).  I can tell you that if we keep our tanks unused and untreated here, even for little over a week - it can become an issue.  The marina engine shops are busy here.

[MarshMarlowe196]

OK, I am certainly not arguing with you, but I saw it with my own eyes in my marine mechanics shop, he had 2 quart jars with typical ethanol gasoline, one with Stabil- and one without, the water in the one without Stabil was UNREAL and the one with Sta-bil  had virtually no water at all.   I am far from a mechanic but it sure seems like all that water couldnt possibly be good for any engine.

That's interesting.  I don't work for Conoco, or Shell or anything, so of course most of this information is 2nd hand.  Seems that no-one really knows for certain (yet) what the actual effects of Ethanol will have on an engine.

Here's something on the subject:
http://www.boatus.com/seaworthy/ethanolwinter.asp

This is the consensus on the main to contributors to gasoline breaking down (becoming less volatile):

1. Exposure to UV light
2. Oxidation
3. Evaporation of volatile components
4. Adsorption (not absorption) of moisture

Stabil creates somewhat of a "vapor barrier" in a gas tank, which helps prevent moisture vapor in the air from entering the fuel, and prevents the volatile components from evaporating.  But if water were introduced in a liquid form (condensation, rain, etc), the stabil could not prevent it from entering the fuel.  Fuel without Stabil would begin to break down faster since Stabil would not be there to prevent the evaporating of the "volatile components".   The faster breakdown of the fuel would lead to quicker "phase separation" (in ethanol fuel).  If enough liquid water got into the fuel, stabil could not prevent phase separation.

When ethanol absorbs the moisture/water, it can no longer be distinguished from gasoline, like you would normally see with water and gas in the same container.  It has become "part of the fuel" at that point.  As more and more moisture is absorbed, it begins to lose octane, but will still burn.  If enough absorption occurs, then you will actually see the "phase separation", which turns into a watery, corrosive solution that is not nearly as volatile as gasoline, and begins to separate from the gas.  My guess is that's what you saw in the jar.

I'm not saying it's bad idea to put Stabil in your tank, I just think that if you're using your boat regularly, like every other weekend or more, it's not necessary to add it into every fuel fillup, especially at $20 a bottle.

Of course, I could be completely wrong, but that's just my thoughts.

I do have a question about the experiment though-  was water added to the fuel?  or was it just adsorbed in the atmosphere?  if it was adsorbed, how long did it take for the watery substance/water to appear at the bottom of the jar?  

Another product to also consider is K100 (http://www.k100fueltreatment.com/).  The E10 problem (racket) is quite the problem here in the northeast and this product works very well.  It actually encapsulates the water molecule and acts as a lubricator.  Not all treatments are the same.  Another that i use is Star Brite's Star-Tron Fuel Treatment (http://mystarbrite.com/startron/) but prefer the K100 overall.

Also, every state is different regarding the content/makup of the gasoline sold (http://www.mobil.com/USA-English/GFM/Fi ... ne_Map.pdf).  I can tell you that if we keep our tanks unused and untreated here, even for little over a week - it can become an issue.  The marina engine shops are busy here.

.

that's a pretty cool map.  looks like fuel here is marked conventional, but we still have 10% corn at the pumps... ?  

a product called Pri-G now claims to stop phase separation, no matter how much water is added...

[lynnstrick01]

Hey Badon::

Boy that was a lot of techy stuff you said there,  hard for this country girl to keep up with... as to your question about the gas in the jar experiment,  I am pretty sure it was absorbed thru the atmosphere because if it was just added to the gas that wouldnt prove much...  It was at my marine mechanics shop and he isnt much for putting stuff out just to sell products unless he has seen it for himself and really believes in it, but as far as how long it took I am really not sure,, I think he told me it was just a few weeks but I couldnt swear to that.  

I just may do my own little quart jar experiment and see.

With the tiny bit of knowledge that I have in these things, I would agree with you that if you are running your boat every week-end it probably wouldnt make enough difference to warrant the expense.  My little boat only carries 6 gals and gets used a lot, summer and winter alike, we dont put anything in that tank but the big boat carries 120 gals  and  beetween work schedules and weather  we are lucky if we get to use it once a month so for that one the cost of the Sta-bil is definitely justified.