Recommend Fuel Tank Tester; Finding Source of Water in Fuel

[matt22c]

I have a 1989 22' Outrage Cuddy Whaler Drive with twin Yamaha F115 engine and the original fuel tank. Yesterday, I went out, and made two- miles down the creek, and the first engine died. I turned around, got back to about 100-yards of my dock, and the second engine died.

The boat was pulled [from the water]. Both fuel filter bowls on the outboard showed water--a red plastic indicator was floating in bowl.

The fuel tank was pumped out. There were about 12-gallons of water [in the pump output] before [the pump output] turned to gasoline. A total of 25-gallons was pumped out, including the water. [The tank level] gauge was slightly above 1/4-FULL.

Last Sunday, 40-gallons of gasoline were added, on top of 20 gallons of treated gasoline from last year. Ring Free was added. I did not use any other treatment. The fuel came from a fuel dock on the water.

This past Tuesday the boat ran the boat all day, from Dundalk to Love Point and Bay Bridge, burning 35-gallons of the new and old gasoline. Then the boat sat until Sunday. The boat lives in the water in Dundalk at a floating pier.

We have had rain, but having 12-gallons of water in the tank from the rain we had seems difficult.

Both rear sump pumps are working. [There is] no gasoline in the sumps.

After pulling the rear access hatch, there was a slight smell of fuel around pickup hoses. After pulling middle hatch there was no fuel smell. Pulling fuel tank level gauge window cover produced no fuel smell. The deck caulk is in good condition. The cuddy leaks and there were four-quarts of water in the forward bilge. I the float switch high in the bilge and will not turn on until there is a good amount of water down there.

I had the boat shrink-wrapped over the winter. I replaced the inline water-fuel separator filters and on-board filters fuel filters as part of the full service. No water was present during service.

Game plan is to pressure test the tank.

Any recommendations on mechanic or person that could do this for me?

What else is there to check?

I am not sure how that much water got in the tank in a few days. Never had a water [in the fuel tank before]. I had the tank checked when I bought the boat in 2014.

I got the outboards running on a remote tank. Had to purge all bad fuel from the fuel pump, fuel rails and lines etc. Pain but they started and idled fine.

[matt22c]

Talked to my mechanic. He thinks it was condensation build up from over the winter and years. I have never drained the tank fully or run the tank down that low.

[Phil T]

If you had ethanol blended fuel and condensation, the fuel could have phase-separated. The water part is not all water. Good that you drained it all out.

For more information on phase separation: https://www.westmarine.com/WestAdvisor/Busting-Ethanol-Fuel-Myths

Check the fuel fill hose (from gunwale to the tank) as well as the fuel supply hoses to the filters. The fill hose has an embedded wire in it. They deteriorate from the inside in so don't think it's good because it looks like that on the outside.

If the hoses do not have "alcohol resistant", they need to be replaced.

Water could be entering the tank via the access plate (near sight gauge/sender)

In cold or humid climates, store the boat over the winter with the tanks either empty (as possible) or full with stabilized fuel.

[matt22c]

Thank you for your input. This is the first year that I did not have the tank full over the winter. The fuel is definitely a blend. Only gas available in the Baltimore area.

I will have to look. I have a super console and I believe the forward hatch is blocked.

[jimh]

There is no way that 12-gallons of water could have been condensed in your fuel tank due to diurnal temperature variation. That is just not even remotely possible.

Even if you allow that the impossible happened, and there were 12-gallons of water in the fuel tank from condensation over the winter, how could the boat have been operated for hours without the water reaching the engines?

The most likely source of the water in the fuel tank was from the recent rain, but even that seems hard to imagine--12-gallons of rain water collecting in a fuel tank is quite a huge volume of rain water.

Since the water appear in the fuel after the on-water fuel dock added 40-gallons, that is your most likely source of the water.

[jimh]

The events in the timeline are presented in a very confusing manner. I believe this is the time line in the narrative:

--Tuesday the boat ran all day burning 35-gallons of gasoline.

--boat sat until Sunday

--[on] Sunday, 40-gallons of gasoline were added, on top of 20 gallons of treated gasoline from last year.

--[on that same Sunday] [both engines died]

--both fuel filter bowls showed water

--the fuel tank was pumped out.

--output was 12-gallons water, 13-gallons fuel

Counting up the fuel, I get:

--35-gallons burned on Tuesday
--20-gallons remained after Tuesday
--40-gallons added on Sunday

This suggests that the tank level prior to Tuesday must have been about 55-gallons. Then 40-gallons were added. This means there should have been 95-gallons in the tank. Then 35-gallons are burned, so we should have 60-gallons left. But when the tank was pumped only 25-gallons came out. We are missing 35-gallons.

Please straighten out the narrative. Give the amount of fuel in the tank at each point, and how much was burned or added. As it stands, it does not add up right.

[floater]

On my 88 Revenge WT 20 I too had water in the tank that stalled both engines. In my case the only thing I could find was the gasket for the fuel pickup plate had corroded and had a split in it. Every time it rained more water would leak into the tank. The tank did have some crevice corrosion on it but no major holes were seen. The tank cavity seems to hold water after every rain fall soaking the foam and covering the tank with standing water. When I put the tank back in I didn't replace the foam and now pump out any water that gets around the tank.

[matt22c]

...Please straighten out the narrative. Give the amount of fuel in the tank at each point, and how much was burned or added. As it stands, it does not add up right.

--put boat in the water on April 13. Tank level was 1/8-FULL or lower
--add 40-gallons fuel April 16
--fished April 18t. Burned 35 gallons. Tank level was 1/4-FULL
--boat sat from 18 to 23 without running.
--checked beoat [April 21] after work; did not start engine
--pulled boat April 23 and pumped out 25 gallons total, water and gasoline.


Just checked the fill and vent line on the gunwale. Both are from 2007. I removed the small deck plate for fill and vent. [Hoses were] same age. No gasoline smell in rigging area.

[Acseatsri]

If the hoses are newer and the tank gage gasket isn't leaking, then you probably have a pinhole in the bottom of the tank.
When I had my tank replaced, the outside of the tank was in pristine condition, no corrosion at all. There was a tiny pinhole in the bottom rear center of the tank near the fuel pickup , not even visible if not for a small wet spot on the bottom of the tank. The only telltale the tank was leaking was a slight gas odor in the cabin when the tank was full.

[quickenberger]

If you have to replace the fuel tank here is an example of what I think is good to do.

I painted the fuel tank cavity.

image (1).jpeg (73.12 KiB) Viewed 30878 times

I foamed in the fuel tank

image (4).jpeg (78.03 KiB) Viewed 30878 times

I removed excess foam and sealed with a polyurethane sealant; expansion and contraction due to temperature will cause air bubbles in the sealant so be aware of that.

image (5).jpeg (72.99 KiB) Viewed 30878 times

Time will tell if this is a good solution to having exposed foam where water can soak in.

I saw a recent episode of Florida Sportsman Dream Boat where they are restoring an Outrage 18. They glassed the fuel tank in place and glassed the deck hatch in place. This is a terrible thing to do since you have to cut out the hatch to get access to the fuel tank.

[jimh]

--put boat in the water on April 13. Tank level was 1/8-FULL or lower
--add 40-gallons fuel April 16
--fished April 18. Burned 35 gallons. Tank level was 1/4-FULL
--boat sat from 18 to 23 without running.
--checked boat [April 21] after work; did not start engine
--pulled boat April 23 and pumped out 25 gallons total, water and gasoline

I don't see the event listed when the engines stalled. When did it rain?

There must not have been water in the fuel on April 18, You burned 35-gallons of fuel. If the fuel tank contained half water and half gasoline, you certainly would have encountered a problem on April 18. That rules out your mechanic's theory that the water came from condensation over the storage period from diurnal temperature change.

The rain event is not listed in your time line. If the rain event occurred after April 18 and before April 23, and the engine stall event was April 23, then the water in the fuel tank probably came from rain, and the fuel tank has some opening that allowed water to enter. I would expect the opening must be on the top of the tank. If the opening were on the bottom of the tank then gasoline would be continually leaking out and saturating the foam surround. You would be able to smell that.

[jimh]

To be able to recommend someone local to you that could test the boat's fuel tank, you have to tell us where the boat is located.

[quickenberger]

Looks like Dundalk is in the Baltimore area.

[matt22c]

The boat is in Dundalk, MD.

[jimh]

Looks like Dundalk is in the Baltimore area.

Thanks for deducing the location of a port where the boat "lives in the water."

[jimh]

The boat is in Dundalk, MD...

Thanks for confirming the location of the boat. This will make it easier for readers to recommend someone who can test the fuel tank in the boat.

[matt22c]

I don't see the event listed when the engines stalled.

Stalled on the 23rd.

The [mystery] that I am having: how did that much water get in the tank in a week? It rained but not that much. The tank would have to have a major hole or crack in it. I have the boat on the trailer now and it has been raining. I am going to check the tank this weekend and see if it has any water in it.

I put 200 hours on it last year with no water-in-fuel problems. Knowing how a outrange is designed. how can that much water enter the tank? I am going to lift the rear deck plate. The front of the tank around the [tank level] gauge is bone dry. If there is a hole in the top it has to be in the rear.

[jimh]

Based on the most recent additional information, I understand the time line as follows:

--April 13: put boat in the water (after long storage period); tank level was 1/8-FULL or lower
--April 16: add 40-gallons fuel
--April 18: ran boat and burned 35 gallons; afterward tank level was 1/4-FULL
--April 18 to April 23: boat sat; rain occurred
--April 23: ran boat and engines stalled due to fuel contamination with water; hauled boat onto trailer; pumped out 25 gallons total, consisting of 12-gallons water and 13-gallons gasoline

Let us examine possible sources for the water in the fuel.

First we have to solve the mystery of how much fuel was in the tank on April 13. At that time the tank level was 1/8-FULL. On April 16 there were 40-gallons added. We do not know the tank level. On April 18 35-gallons were consumed, and the tank level was 1/4-Full. From this we can deduce that the net change in fuel volume in the tank was 5-gallons, and this caused the tank level to change to 1/4-FULL from 1/8-FULL. This defines the 1/8-FULL level change as 5-gallons, and from that we deduce the tank capacity must be 40-gallons. This is contradicted by other data in the narrative, because on April 16 40-gallons were added to a tank already at 1/8-FULL. This means the tank capacity was more than 40-gallons.

Next we consider the remarks that when the tank level was 1/4-FULL, there were 25 gallons in the tank. This suggests the tank volume was 100-gallons. If we accept 100-gallons as the FULL capacity, then on April 13 there was about 12.5-gallons in the tank. Then 40-gallons were added, 35-gallons were consumed, so the net was 5-gallons added. Thus after April 18 there would have been about 17.5-gallons in the tank.

When the tank was pumped out on April 23 the total volume was 25-gallons. If there were 17.5-gallons of fuel in the tank on April 18, then about 7.5-gallons of water had to enter the tank between April 18 to April 23. This is based on the reports of the tank level gauge, fuel added, and fuel consumed.

CONDENSATION
A mechanic suggests the water in the fuel came from some period of storage of the boat during which diurnal temperature variations caused water vapor above the fuel in the tank to condense into water and mix with the gasoline. We don't know if the gasoline was pure gasoline or a blend of ethanol and gasoline. Pure gasoline has little tolerance for water in solution, so any water created during storage would have separated from the gasoline and should have settled to the tank bottom. Ethanol-gasoline blended fuel can tolerate more water in solution, but only about 0.5-percent. (This data come from an EPA paper.)

As noted above, the water had to have been introduced between April 18 and April 23. There is no way that at any time a volume of 7.5-gallons of water-and-ethanol could have stayed in solution with the fuel. To keep 7.5-gallons of water-and-ethanol in solution with gasoline, the water content must have never been higher than 0.5-percent.

We analyze this as follows:

Let G be the volume of gasoline. Let E be the volume of ethanol. If the ratio of E to G is 1:9, then we can define E as 0.1*G. The total fuel volume is thus E + G or 1.1G.

Let W be the volume of water. To keep water in solution, at no time can W be greater than 0.005*(1.1*G) or 0.0055*G. If we figure there was at least 45-gallons in the tank when the boat was run on April 18, and the boat ran normally, this suggests that the amount of water had to be less than 0.0055*G, where G is 0.9*45-gallons. Solving for W gives 0.2-gallons. That is the maximum amount of water that could already have been in the tank and have still stayed in solution with the fuel, which is required to have happened because the engines ran normally at that time. This seems to rule out condensation as the source of most of this water found in the tank on April 23.

COMPOSITION OF THE WATER EXPELLED FROM TANK

The "water" pumped out of the tank was described as having a volume of 12-gallons. This probably consisted of water and ethanol, assuming the fuel was a blended fuel. We look at the tank volume remaining after the run on April 18. It is "1/4-FULL" Since we have never been told the tank capacity, we have to estimate the volume. Let us assume "1/4-FULL" means 25-gallons. If the fuel is a blended fuel, it could have ten-percent ethanol, or 2.5-gallons. This suggests that the water portion would be about 9.5-gallons. We know that water from the fuel could not be more than 0.2-gallons. So we need to find about 9-gallons of water to enter the tank.

RAIN

Entry of 7 to 9-gallons of water into the tank seems most likely to have occurred due to rain falling on the boat between April 18 and 23.

[jimh]

What is the fuel tank capacity of the boat under discussion?

What was the approximate volume of fuel in the tank on April 13?

[matt22c]

[The boat has] 129 gallon tank.

[jimh]

The [mystery] that I am having: how did that much water get in the tank in a week? It rained but not that much.

Let us consider how much rainfall in terms of inches of rain must fall over a particular area to accumulate 1-gallon of water. If rain falls at rate of 1-inch-per-hour, we can find surface area of a container that will hold 1-gallon of rainwater.

One gallon is a volume of 231-cubic-inches. If 1-inch of rain falls in one hour, to accumulate 231-cubic inches we need a surface area of 231-square inches. Converting to square-feet that becomes 1.6-square feet.

We estimate the cockpit area of an open boat of roughly the dimensions of an OUTRAGE 25 will have a surface area of 10-feet by 7-feet, or 70-square feet.

Thus if rain falls at a rate of 1-inch-per-hour on an OUTRAGE 25, the cockpit area will collect (70/1.6)-gallons of rainwater, or 43-gallons-per-hour.

We can assume that a 1-inch rainfall that causes the deck to collect 43-gallons of water will not result in every drop entering the fuel tank via a leak, but we only need to have about 7-gallons of water enter the fuel tank. That is only about 15-percent of the total water that would be collected during a rainfall of 1-inch.

ASIDE: several years ago we were staying on the boat at a marina. There was a terrific downpour for several hours. Most of the rainwater collected into the cockpit sump and was expelled by the sump pump, but some entered the aft live well on the deck, getting past the hatch that covered it. In fact, the aft live well was filled to the brim--completely full of water. I was quite impressed with the ability of rain water falling on the deck to get past the hatch cover and accumulate in that live well.

[jimh]

[The boat has] 129 gallon tank.

You can re-work my calculations that were based on a 100-gallon tank with the new data that the tank has 129-gallons. The outcome should be that the possible amount of water already in solution in the fuel would increase by 1.29, or to about 0.26-gallons of water from 0.2-gallons of water. I don't see that as altering the conclusions I reached.

You may want to make these calculations yourself. I could have made an error. But, so far, I can't see that the volume of water and ethanol you pumped out could have come from condensation.

By the way, what sort of fuel was in the tank? Was it blended ethanol-gasoline? Or just gasoline?

[jimh]

...I removed excess foam and sealed with a polyurethane sealant...Time will tell if this is a good solution to having exposed foam where water can soak in.

Thanks for the description and images of your modification and repair to the fuel tank cavity and installation of a new tank. Please keep us posted on the outcome of sealing the tank foam top layer. That does sound like a reasonable approach, as long as there were no water already in the foam.

[matt22c]

By the way, what sort of fuel was in the tank? Was it blended ethanol-gasoline? Or just gasoline?

Ethanol blend. Unfortunately it is the only fuel available in the area.

[jimh]

I calculated the water content using ethanol-blended fuel. The figures should be applicable.

I used to have a mystery water accumulation in one of the sumps of my boat. I could never figure out where the water came from. I was going to test it by using some sort of water-tinting. Get a bucket of water and throw something into it that would tint the water--but would not tend to tint the gelcoat. Then throw the bucket of water on the deck and see where it went. The problem was figuring out what I could tint the water with that wouldn't tend to tint the gel coat, too. Eventually I discovered where the water was coming from--it was running into the cabin from the cockpit sump when I trailered the boat; I had to descent a very steep hill, and any water in the aft sump was running up the rigging tunnel and spilling into the forward sump in the cabin. But water can be sneaky. It finds ways to go where you wish it would not go.

Have you looked carefully at the filler hose where it runs across horizontally under the deck? That hose can deteriorate and become permeable. If it sits in water at a low point in the tunnel running across from the gunwale to the tank, water could enter the fuel tank by passing across the permeable hose.

[quickenberger]

Have any other boats in the area complained about water in their tanks? Maybe the place you fueled up had bad gas?

[jimh]

Maybe the place you fueled up had bad gas?

If the fuel that was added to the tank on April 16 contained 12-gallons of water, why did the boat operate normally on April 18 when 35-gallons of that fuel was consumed? This is an apparent conflict in the causation theory that suggests the water came into the tank in the fuel itself. If the time line is reviewed, I think you will see this problem.

[quickenberger]

I guess I got lost in the sequence of things. Seems like rain is the most plausible culprit. Small amounts of rain over a large surface area equates to a lot of water. That much water getting into the tank is a probability. It is a possibility that the tank developed a pinhole, crack, or degraded hose/gasket that finally opened up and then let the rain water in.

The manufacturer pressure checks these tanks to around 3 PSI IIRC. If a technician were to seal off the tank, then use a very accurate pressure regulator and pressurize the tank, soapy water will reveal where a pinhole or leak might be. I'd start with the access cover, fuel tank sending unit, and fill/vent tube weld areas. If that checks out okay then use soapy water around the perimeter of the tank where the foam is. I don't think the whole hatch would have to be removed for this check if you use mirrors and flashlights.

[Acseatsri]

If it were my boat, I would just replace the tank. At 30 years old, it's definitely at life's end, probably not worth the effort to confirm that a hole is present.

[matt22c]

If it were my boat, I would just replace the tank. At 30 years old, it's definitely at life's end, probably not worth the effort to confirm that a hole is present.

I don't disagree with the above. Just do not want to replace a tank that has life in it and sit out most of my fishing season. Has anyone had a estimate for a tank replacement recently?

I am going to check the tank on Thursday to see if there is any water. We got a ton of rain today, so i should have water if there is a hole in the tank. I have not found anyone to presure test the tank so I think I will use a hose to test the concern as its on a trailer and there is no gas in the tank.

[pLee]

Matt--last October and November I was in the same situation as you: water in the tank from some unknown source.

There were four corrosion holes the size of a pencil erasure up near the fill and vent hoses, right in between the two. Water got in the tank when it rained. My go-to shop guess-etimated $3,700 to replace the tank. I replaced it myself over the winter. It was a LOT of work, but you can save a lot of money. I'd say I spent less than $2,000 and learned a lot about my boat in the process--and fixed a lot of weird stuff, mostly goofed up wiring. $500 of that was for a new alarm module.

BTW, I pressure tested the tank with a shop-vac. I blew air in the filler nozzle and smelled and felt the air around the various access ports. Not very scientific, but it worked for me.

Also, I got the new tank from Atlantic Coastal Welding in NJ. They had drawings of the stock tank. I'd definitely use them again.

Hope this helps.

[Blackduck]

The tank in your boat is almost thirty years old. ALL of the Outrage tank cavities of the 70's and 80's leak to some degree, due to poor design, and even with the best of care, leak rain water. Getting the tank pressure tested will most likely confirm that it is leaking. You can do it yourself, just plug the lines, and put in only 1 or 2 pounds of air, no more. Like I said, chances are, its time for a new tank. Water sitting on the raw aluminum will eat holes in it in very short oder. I just replaced a tank in a boat that had it's tank replaced in 2003, it was a hack job, but even so, that tank failed in less than 10 years.

[jimh]

If replacement of the fuel tank is contemplated, one might consider changing the size of the fuel tank to the smaller 77-gallon tank option. With modern engines like twin F115 Yamaha four-stroke-power-cycle engines, I would expect that a tank capacity of 129-gallons would give very great range. The boat ought to average about 3-MPG overall, and 129-gallons of fuel might give a range of over 300-miles. My REVENGE 22 W-T Whaler Drive has the smaller 77-gallon tank. I find that a full tank gives me plenty of range, about 200-miles, sufficient for several days of operation of the boat without refueling.

A smaller tank will likely cost less. The fuel will turn over faster in the smaller tank. Unless you really need the 129-gallon tank, going smaller could be an option. On the other hand, there may be some mechanical problems to be overcome if the tank size is changed. There is likely a missing bulkhead in the tank cavity.

[matt22c]

That is my plan. 129 gallons is far to much gas for how I use the boat. Besides storing the boat I never fill above 1/2 tank. This gives me plenty of range and worst case there are plenty of fuel docks along the bay.

I am meeting with a welder this afternoon to discuss a above deck temp tank. I have not been able to find a temp tank that has two fuel pickups. Not sure how difficult it is to add one to this type of tank. https://www.wholesalemarine.com/moeller ... 87804.html

[matt22c]

Temp tank installed. Need to run the fuel lines. 35 gallon moeller tank.

[matt22c]

Pulled the rear plate. Tank is bad. I am thinking of digging the foam out in the rear and putting a bilge pump down there. The foam is wet at the rear of the tank. Should I put a bilge pump down there? Tank is completely empty of fuel.

[Phil T]

Several members have installed pumps with mixed results. Given that the tanks usually last 25+ years, it is a toss up. There are lots of threads in the archive you can read so as to make an informed choice.

I am expecting to replace my tank eventually. Having read/followed tank replacements for 10 years, I plan block the tank using plastic spacers and not use foam at all. Any water will evaporate.

Rather than add a pump, some attach a hose to the rear wall and run it aft. They attach a pump to it manually when needed.

[matt22c]

Thank you for your reply. I am leaving the old tank in there for now. I have a spare pump and may dig the foam out as it is pretty wet in the rear. I don't want water to collect back there.

[matt22c]

Got the foam in the rear out plus 16 gallons of nasty, stinky water.

[quickenberger]

It does have a very strong nasty smell. When you are in the position to replace the tank I can get you hooked up with the guys that cut and bent the aluminum for mine. The material plus bending was ~$270.00. I welded it up but they also have certified welders, so if you want, I will get a quote for them to weld it too. My tank was 93" long, 23" wide and 8.5" deep at the deepest point (external dimensions). I have SolidWorks as well and can model any tank design if you need.

P.S. There is a 4 week lead time on the fab shop.

[matt22c]

When you are in the position to replace the tank I can get you hooked up with the guys that cut and bent the aluminum for mine.... if you want, I will get a quote for them to weld it too...

Great. I will take you up on the above in the winter.

Got the rest of the fuel out of the tank last night and starting installing the fuel lines--almost back in the water. Two or three nights of work remain.

[msl73]

On my [1984] Outrage 25 [I] just had both 70-gallon fuel tanks replaced by Whalertowne in Chestertown, Maryland. The forward fuel tank had electrolysis. Its bonding wire had broken completely free from the tank, and there were a six eraser-size holes on the top side. During the demolition of the forward tank I removed 55-gallons of fluid. Of the 55-gallons, only 10-gallon were fuel and the remainder was water. I did all the [demolition] work removing the old tanks.

took the old tanks to Whalertowne, and they had a local fabricator on Kent Island weld new tanks based on my old ones. I had Whalertowne install the new tanks--only the tanks--and I am now in process of putting the boat back together. The cost for them building new tanks and installing them was under $2,000.