1986 Outrage 20: Water in Fuel Tank

[ekalb]

[This topic about making repairs to the fuel system of a Boston Whaler boat has been moved to the REPAIRS and MODIFICATIONS forum for discussion from another forum--jimh.]

BACKSTORY: I picked up a 1986 Outrage in 2019 Spring. It came with a 1998 Yamaha 200-HP carburetor engine. We put on about 20-hours this summer with zero hiccups. The engine ran flawlessly across all RPM ranges.

When I first got the boat the fuel sending unit was missing; I replaced it. I can't remember if [the replacement fuel sending unit] came with a gasket--I believe it did. I will double check that on August 29, 2019.

In early August 2019 I made my way out to the mooring and found about 4-inches of water on the deck, all towards the stern. [The cause of having so much water collected was because] the power to the sump pump became disconnected. I [reconnected power to the pump]. I pumped out the water that was sitting on top of the fuel tank. With the water removed, I fired up the boat and cruised for about five minutes before [the 1998 Yamaha 200-HP engine] sputtered, sneezed and died. I assumed there was water playing a roll since everything had gone well all summer up until I found the sump pump not pumping.

The last time I used the boat before that incident the fuel tank was at 7/8-FULL. We never once caught any fuel odors all summer or any time I opened the inspection port. There was almost always condensation on the clear inspection port that would go away as we cruised along.

I feel like water somehow got in on top either by the [fuel tank level] gauge or the fuel [tank] pickups in the stern. I guess [the fuel tank] could have pin holes all over the place. Really anything is possible.

I just pulled the boat out yesterday. Below are photos of samples of what I pumped out from the [fuel hose primer] bulb [as compared to] fresh gasoline:





Q1: What do the experts think I should do to properly diagnose [how the fuel became contaminated with water]?

Q2: Should I drain the fuel tank of all gasoline and pressure test the tank?

I don't mind just doing the work to replace the tank in the spring, but if it can be avoided, that would be ideal.

[jimh]

I am not clear what component of the OUTRAGE 20 fuel system you are describing as "the fuel sending unit." Please elaborate and give a better description of this component.

[jimh]

Re the fuel in your fuel tank now: it appears to be contaminated. If the tank was 7/8-FULL, and the boat has the usual 77-gallon fuel tank, then you probably have about 55-gallons of contaminated gasoline fuel.

The first problem set to resolve is how to remove 55-gallons of contaminated gasoline fuel from the tank. If the gasoline was pure gasoline and contained no ethanol, you may be able to recover the gasoline. Obtain a very good fuel-water separating filter. Run the gasoline through the filter. As the water is separated, discard the water, while keeping the filtered gasoline. About eight 6-gallon portable gasoline containers may be needed. Or, you can test a sample of the filtered gasoline in some other gasoline engine, perhaps a lawn mower or and older automobile. I wouldn't try using the gasoline in a modern, sophisticated car engine--not worth the risk of damage to the engine.

If the gasoline was a blended fuel containing ethanol and gasoline, there is probably no hope for recovery of the gasoline. Once the ethanol has been removed from the gasoline and bonded with the water, the remaining gasoline will have very low octane. It won't be useful in any engine expect perhaps older very low-compression simple engines, a lawn mower engine perhaps.

Once the internal fuel tank on the 1986 OUTRAGE 20 is empty of gasoline, you can assess the path of ingress for the water. If the component that was missing when you initially bought the boat and then replaced needed to have a gasket, and if there was no gasket, that component could be the location of the ingress of water into the fuel tank from water sitting on the top of the tank.

[ekalb]

I am not clear what component of the OUTRAGE 20 fuel system you are describing as "the fuel sending unit." Please elaborate and give a better description of this component.

Poor choice of words on my end. I meant fuel gauge unit. When I bought the boat the top magnetic gauge was missing. I replaced the full assembly, so I would have a working gauge I could see.

[ekalb]

...The first problem set to resolve is how to remove 55-gallons of contaminated gasoline fuel from the tank...

My plan was to just siphon out all the fuel into 5-gallon jugs, which oddly enough I have way more than necessary for this. My local transfer station will dispose of the fuel.

Do you think there is a good way to test for egress without de-rigging and pulling the entire deck cover off?

[jimh]

Do you think there is a good way to test for egress...

If fuel were leaving the tank ("egress"--the action of going out or leaving a place) then a fuel leak will be obvious and easy to locate by odor.

You are looking for an ingress path, a way that water is getting into the tank, most likely from the top of the tank where the rain water was accumulated. There are [four] inlets or outlets in a tank:

--fuel filler, a 1-1/2-inch hose
--tank vent, a 3/8-inch hose
--fuel pick-up, a 3/8-inch hose
--[added a fourth; the fuel tank level access circular plate]

If you can figure a way to seal off all but one, then you can pressurize the tank and test for leaks. If you pressurize the tank limit the pressure to only 2 or 3-PSI. Check the Florida Marine Tank sticker for advice on maximum pressure to use in testing.

Also, there is a real possibility that water got into the fuel tank in a very simple way: it came in with the gasoline fuel you bought when you filled the tank to 7/8-FULL earlier, before the rain water accumulated. The accumulation of rain water might be coincidental with the water being in the tank already. Review your use of the boat from the time you bought the fuel to the time the engine quite running due to water in the fuel.

[ekalb]

My tank was filled all the way that last time I used the boat. I put in 33 gallons. I burned off that 1/8th-tank volume on my way back to my mooring. It could be coincidental, but my gut just kept saying the bilge not working and all that water sitting on the tank had to be the main contributing factor to water getting in the tank. I don't know that for sure though.

Thanks for all the advice so far.

[Phil T]

Given the history of use with the boat, I would proffer that you have a leak in the existing O ring on the fuel gauge plate (direct read or remote) or it is missing in its entirety.

If there was a leak in the tank you would see a sheen of fuel on the water you removed from the boat. If there was a leak in a fuel vent or supply, you would smell gasoline.

Make sure the material that you use to seal the fuel gauge plate is rated for gasoline.

[jimh]

[By "the fuel sending unit"] I meant fuel gauge unit. When I bought the boat the top magnetic gauge was missing. I replaced the full assembly, so I would have a working gauge I could see.

Okay--the fuel tank level gauge mechanically actuated by a float in the tank and coupled magnetically to a dial pointer. There certainly should be an air-tight seal for that hole in the fuel tank.

[ekalb]

I will start digging around there later today.

thanks!

[ekalb]

I just took apart all the inspection ports and took some photos. The tank is original (1986)

I removed the fuel gauge assembly and there was a new gasket there from when I installed it in June. I am not sure it was perfectly seated and you can see an outline of how it sat on the underside of the gauge in one of the photos. It definitely wasn't on there perfectly and when I put the gauge assembly back on, I was able to tighten it down more than it previously was. Not sure if water made it in that way or not.

There is a gasket aft where the two pick-up tubes are on the aft side of the tank. I can feel around maybe half of it, but the other half I can't lay eyes on since its not centered at all around the inspection port.


Does anything jump out at anyone with this photos?


Fig. 1. gasket around the two fuel pickups



Fig. 2. fuel gauge assembly removed



Fig. 3. Underside of Fuel gauge assembly



Fig. 4.


Fig. 5. original sticker on tank showing a build date or 1986


Fig. 6.


Fig. 7. Fill and vent hose

[jimh]

Does anything jump out...[in these] photos?

Based on the general condition of the tank surface and its attachments, I would infer that the recent ingress of water into the tank area was not the first occurrence of such water ingress. The black coloration may be from mildew. Mildew grows well in fresh water, so the water intrusion was likely from accumulated rain or wash-downs with fresh water.

As a comparison, the top surface of the Florida Marine Tanks 77-gallon fuel tank in my 22-foot hull is a matte light-green paint finish of what I presume is aluminum anti-corrosion primer, and there is almost no sign of black mold or mildew anywhere.

The label in Fig. 5 shows the maximum test pressure as 4-PSI.

What is being illustrated in Fig. 3.?

If captions were added to the illustrations the readers will have a better idea of what is being shown.

[ekalb]

I updated the photo descriptions. thanks

The boat was used in freshwater for the last 9 years until I put it in saltwater this season. I haven't spent much time at all washing the boat this year, so I would think the mold and mildew is from rainwater. It did look mostly like that when I picked the boat up, so I'm sure it has been growing for years.

Is there any point trying to figure out the ingress path at this point?

Or should I just plan on ordering up a new tank from FMT over the winter and start fresh next season?

Obviously, I would rather somehow get the tank fully cleaned, put fresh fuel in, and go on with boating, but I don't know if that is realistic or not.

[jimh]

Is there any point to me trying to figure out the ingress path at this point? Or should I just plan on ordering up a new tank from FMT...

I would assess the situation as follows:

--a new fuel tank from FMT will probably cost over $1,000; tearing out the old tank will be a lot of work, and probably dirty work; ditto for putting in the new tank--a lot of work

--because the water did not show up in the fuel tank until a lot of water accumulated on top of the tank, I would infer the path of ingress is in the upper surface of the tank, not buried somewhere lower

--before undertaking all the expense and labor of replacing the existing fuel tank, you should be sure it really has a leak that can't be fixed with something simple and easy like gaskets or sealant.

Also, I think you should check the integrity of the filler hose. Here's my thinking:

--your boat dates from 1986; this is right at the epoch when marine rubber fuel hose began to be rated for alcohol resistance. Generally a boat made c.1987 would have fuel hoses with clearly marked "alcohol resistant" indications, but a 1986-era boat might not have that type of rubber fuel hose;

--today it is very common to get gasoline with a blend of ethanol and gasoline in a 1:9 ratio; in some cases the ethanol content is higher than that; such fuel can work on old rubber hoses and cause damage;

--the big diameter fuel filler hose is typically NOT rated for continuous exposure to gasoline in the line; the expectation is that this hose is just a tank filler and the gasoline will only be passing through it momentarily on its way to the fuel tank; however, if the tank is filled to to "full" there could be fuel backed up into the filler line; there could also be some fuel left sitting in a low spot in the filler line as it runs horizontally across the deck; fuel left sitting in the filler hose tends to weaken the hose walls until they become permeable;

--if enough water was accumulated on the top of the fuel tank and on the deck, the filler hose could have been submerged in water; if the filler hose has a soft spot and has become permeable, and if it sat in a bath of water for days, water could have passed through the hose wall and into the fuel tank.

--replacement of the big filler hose, particularly the horizontal portion, has been necessary in many c.1986 boats.

On the basis of the above, you ought to take a close look at the fuel filler hose condition and look for evidence of soft spots, leaks, or hose wall failure and permeability.

[jimh]

Thanks for adding captions. They're very useful.

[ekalb]

I am fairly certain the fill hose was dated c.2006. When I first picked the boat up, the panel that covers the fill and vent hoses on the port side was coming off and I thought I saw a date.. I will double check.

Either way, Im sure [the fill hose] needs replacing.

I will poke around the boat more toward the end of the weekend.

I can't thank you enough for the advice.

[floater]

On my 1988 Revenge 20 W-T I also had water in the fuel tank. After getting the fuel tank refurbished and coated with a urea based covering, I had water get into the gasoline again the following season. Turns out the gasket at the fuel pick-up plate was the cause.

Water had gotten into the boat during the winter months and the tank was completely covered come spring. Since the original FMT gasket was over $80 to get here in Canada, I ended up making a gasket out of gasket making material from an Auto Parts Store. The first gasket failed. I made another gasket using a sheet of cork. I sealed this gasket with Butyl tape and it's been two years now with no more water intrusion.

I say replace all fuel hoses and the fuel pick-up plate gasket. After installing all my hoses, gaskets, and tank into the fuel tank cavity, I sealed off all the hoses and inlets. I filled the fuel tank cavity area and top of tank with soapy water. I waited for all the bubbles to disperse then blew into the vent hose. You could see the tank actually expand a bit. I pinched off the vent hose and checked for bubbles.

[jimh]

FLOATER describes his tank leak testing method:

...I sealed off all the hoses and inlets. I filled the fuel tank cavity area and top of tank with soapy water. I waited for all the bubbles to disperse then blew into the vent hose. You could see the tank actually expand a bit. I pinched off the vent hose and checked for bubbles.

That sounds like a very interesting method. Thanks for passing along your experience.

[Don SSDD]

For all gaskets, I use hylomar universal blue gasket compound on both sides of gaskets like the one in your fuel gauge. It stiffens up but never hardens like an RTV or silicone type product, so won’t clog filters. It was invented for aviation and it good for fuel of any kind, great for carb gaskets and these new o ring type head gaskets. Evinrude or mercury supplies some of this in a small package with their carb kits I think.

My 1986 boat had original fuel lines--they were very flaky. The fuel fill hose has a metal wire inside it; it was rusted a lot. My 1991 fuel tank leaked water like yours after the boat flooded with rainwater. A pressure test confirmed tank failure. I never smelled gasoline before the pressure test pushed gas out of the tank, but the rainwater entered the fuel tank somewhere.

[ALAN G]

Given the age of the boat and fuel tank, and water in the fuel tank:

• You ought to pull the tank deck cover. Not only do you need to replace the fuel lines (for existing tank or replacement tank), but you need to do an air test. You must determine if the tank itself is leaking, either at one of the gasketed connections, or if it has succumbed to pin hole corrosion on the tank top or elsewhere.
  
• As mentioned in the advice above, you need to get rid of the bad gasoline=water mixture. It is somewhat easier if you have access to the other tank openings, which you will have once the tank deck cover is removed. And the tank must be completely emptied of such fluid.
  
• Do the easy and cheap stuff first. Pulling the deck cover is well within most Whaler owner's capability. Since the boat is 33-years-old, the sealant around the tank top and the screws holding it down is due for renewal. You will also have a chance to check the deck cover itself. I know you are not looking for more work, but you want to know the deck cover, which is a composite sandwich of fiberglass and plywood, is in good condition and not deteriorating, the fiberglass underneath the plywood delaminating, or the plywood rotting. These conditions are common on older Boston Whaler boats. There is plenty of info on rebuilding a deteriorated deck cover.
  
• Once you have done the air test and identified the source of tank leakage (if any) you can make the big and expensive decision to keep or repair the existing tank, or to go the expensive route and replace the tank. Up to this point, your expenditure will be mostly sweat equity.

I recently completed a tank repair on a 1973 Outrage 19. Even though the boat was always used in fresh water since new (Colorado, bought from the first owner's family), it had several perforations on the tank top--and several gallons of water in the tank. This is because on many Whalers, the drains designed into the boat do not fully drain standing water off the top of the tank. The rectangular cavity (which holds the foam which holds the tank) has edges higher than the tank top. If the drains for the tank top are not level with the tank top, water collects. Even fresh water sitting on aluminum can and will cause pitting corrosion that will compromise a tank. On all the Whalers I have owned with installed tanks (1975 Revenge 19, 1990 Revenge 22, 1973 Outrage 19), I have had to correct this drainage by drilling drainage holes through the edge of the [walls of the fuel tank cavity] so water on the tank top can run into the bilge sump.

I use a water tube manometer to determine the pressure and provide a relief valve while air testing the tank. About 55.5-inches of fresh water is needed for 2-PSI, which is enough for leakage testing safely. It is not my purpose here to describe this process in detail since it would be lengthy and should be accompanied with pictures of the process. But if you are familiar with manometers (or you research them), they provide an easy and inexpensive way of measuring the pressure. I used clear vinyl tubing and a household ladder to get enough height for 55-inches of water. If you err and add too much pressure, you just blow the water out of the manometer and relieve the tank pressure.

If you are so inclined, the work is interesting and educational. If you are not so inclined, pay someone else to do it. Good luck, and I look forward to finding out where your water came from.

Al

[ekalb]

Thanks Al. I appreciate all the advice so far. After reaching my hand in each deck plate and feeling around the underside of the deck, the time to record [something] and just replace the tank [is at hand].

I plan to perform all repairs during the winter. This is not my first tank replacement. It is my first tank replacement with foam around the tank. With all the reading I have done on here, I think I should be able to get it out of there.

Obviously the console needs to be removed.

Is it easier to de-rig the boat at the engine side and leave the console wiring intact?

Or should I de-rig the console and pull everything back towards the stern and the engine?

The boat batteries both sit in the seat cooler in front of the console.

The battery switch is aftt under the stern bench seat on the starboard side inwale.

[Phil T]

Derigging at the console is the prevailing way. You can shift the console forward rather than remove it from the boat.

[ekalb]

Derigging at the console is the prevailing way. You can shift the console forward rather than remove it from the boat.

Okay. Your advice makes sense. Thank you.

[ekalb]

[Condensed four posts into this one--jimh]

I decided to go with Coosa board under the 4 x 10-foot section of deck that I will take out. I am going to skip foaming [the fuel tank into the fuel tank cavity].

I will add a self priming pump hose [at the aft end of the fuel tank cavity] to remove any water that gets into the fuel tank cavity. I have seen SHURFLO-brand pumps mentioned, but no specific model. I want [a pump that can lift] any water out of the [fuel tank cavity], something like this:


or this:


Give me a recommendation for a suitable pump [to lift water from the fuel tank cavity].

Also recommend material for the tank to sit on. I have anything from nothing to yoga mats to AZEK-type trim bonded to the tank with 5200.

[jimh]

Re a recommendation for a pump to use to evacuate water from the fuel tank cavity:

Consider a diaphragm-type pump such as a JABSCO 240 GPH Diaphragm Bilge Pump. This pump is self-priming and can lift water six feet vertically to the pump. With this type pump you can mount the pump in a convenient location and just route a hose from the bottom of the fuel tank cavity to the pump. See

https://www.go2marine.com/jabsco-diaphragm-bilge-pump-general-purpose-4-gpm-12-volt-36960-2000

Jabsco, Diaphragm Bilge Pump, General Purpose, 4 Gpm - 36960-2000

pump.jpg (6.26 KiB) Viewed 9704 times

The manufacturer says:

Jabsco Diaphragm Bilge Pump for General Purpose and sump pumping. Open flow rate of 4 gpm this pump may be used for deck washing as well.

• 6 amps@ 12 volt with 4 gpm
• Self-priming to 6', allowing installation above the bilge and sump area
• Design allows pump to run dry for extended periods without damage
• Has a tough plastic body with 3/4" ID ports
• Meets USCG and NMMA standards
• Complete with Pump Guard Strainer

The inexpensive 37202 and 36960 series include many of the dependable features of the classic Jabsco PAR pumps. They are ideally suited for bilge or shower sump installations and come complete with a 3/4-inch suction strainer. They will prime up to 6-feet and will run dry without damage.

I have first-hand experience with a similar pump. I installed one to lift bilge water from the deep sump of a sailboat keel. The JABASCO PAR diaphragm pump easily drew water vertically upward about four feet from the bottom of the sump, then aft several feet into the pump, and blasted it out a transom exhaust fitting at high velocity, throwing it several feet astern. Previously, a centrifugal pump had been installed in the keel sump, and it was entirely unsuitable. Centrifugal pumps cannot tolerate much head on the pump, that is, they cannot lift their output water very far vertically. And, of course, they cannot prime themselves, so they must be lowered into the water they will remove. The JABSCO pump was a great improvement over the centrifugal pump that was previously soaking in the bilge water and unable to remove any water.

The basis for my recommendation to you to use this pump is to remove the pump from the fuel tank cavity itself. This allows the electrical motor that runs the pump to be located away from the fuel tank and any possible gasoline vapor. This eliminates running electrical wiring into the fuel tank cavity.

The price today almost double what I recall it cost 30-years ago. I don't own that boat anymore, but I bet that pump still works.

The problem for use on an OUTRAGE 20 will be where to hide the pump, as it won't look great sitting in the engine splash well.

I hope you find my recommendation and my explanation of the basis for the recommendation to be useful in response to your request to give advice and recommendation for a pump to remove water from the fuel tank cavity.

[Phil T]

Consider this: several members have installed new fuel tanks without foam and hose with a dedicated prime-less pumps. After several years, when asked, the owners said they would not do it again but rather install the screen and hose to connect to a hand or accessory pump.