Water in Fuel Tank, Double Eagle 18.5

[Sue]

We have a "new to us" 2010 18.5 foot Double Eagle. We keep getting water in the fuel. Any suggestions?

 

[Sandpiper]

Hey Sue, Where are the fuel tanks located in your Double Eagle and what kind of Fuel Seperator are you currently using? Also you may want to try a loop in the Fuel tank breather but this is an uncommon point of intrusion.

Dan

 

[N2013]

Replace fuel water separators, check around your gas fill and make sure the hose is in good shape, open up the access hatch in the floor and make sure water isn’t pooling there. Fuel tank vent, etc. Basically
Check everything. Maybe you got bad gas??

 

[Sue]

Thanks for both replies. So far I have found the o ring on the fill tank cap has a slight flaw. Also the fuel tank vent hose drooped down, without and upwards u shape, so I've fixed that. I will open the access hatch tomorrow... I thought the gas tank would be waterproof even if there was water intrusion, but it's worth checking. I got the fuel from Vancouver fuel barge, so I thought it was a safe bet as they must have good turnover. Don't have many choices these days for where to get fuel. A friend told me to put 99% alcohol in the gas tank to break down the water molecules to where they will go through the carb. Had an agonizing trip across the Strait doing only 6 knots, so I don't want to do that again.

 

[salmonkiller01]

I had water in my fuel and found the filler pipe was cracked around the threads allowing water in.

 

[Sue]

Thanks, did you just notice the crack by eye?

 

[Ringo]

Whatever you do, don’t add ethanol to the fuel. Whoever said you should be adding alcohol to your fuel tank didn’t know enough about the reaction chain between water and carbon molecules.
BTW, what kind of motor do you have? Is it an older carb engine or an EFI?

 

[Foxsea]

We had a water in the fuel tank issue a few years ago. It was getting in at the fuel fill cap.

 

[Sharphooks]

We had a water in the fuel tank issue a few years ago. It was getting in at the fuel fill cap.

^^^^^^^^^ this^^^^^^

I had to pump 200 liters of fuel out of a contaminated tank last Fall. There was a blob of emusified crap in the plastic bowl of the fuel/water separator that had the consistency of mayonnaise. It killed one of my Suzuki outboards.

I started examining fuel lines, filler caps etc. I noticed the filler cap “O” ring had a flattened-out section surrounded by what appeared to be salt crystals. It was fitted to the top of the transom. The boat had just done a 6 hour run through snotty conditions (wind blowing waves sideways) returning from the albacore grounds .....

The filler cap seemed to be the logical place where we got the water intrusion into the tank....the outboards pulling fuel create a suction effect ...any salt water hitting the fuel cap got sucked in........

You probably don’t want to hear this, Sue, but if you had the outboard running problems you mentioned, you might consider pumping the tank and having the inside polished. For sure, swap out the filter in BOTH your fuel water separator (external) and the internal one in your outboard

Wouldn’t be a bad idea to clean out the VST (vapor separating tank) in the outboard also

It might have been overkill but I had the tank pumped dry as mentioned, swabbed down with solvent, polished, and ALL fuel lines/water seperators replumbed and replaced

Oh, and a new filler cap...have not had the problem since

 

[Foxsea]

^^^^^^^^^ this^^^^^^

I had to pump 200 liters of fuel out of a contaminated tank last Fall. There was a blob of emusified crap in the plastic bowl of the fuel/water separator that had the consistency of mayonnaise. It killed one of my Suzuki outboards.

I started examining fuel lines, filler caps etc. I noticed the filler cap “O” ring had a flattened-out section surrounded by what appeared to be salt crystals. It was fitted to the top of the transom. The boat had just done a 6 hour run through snotty conditions (wind blowing waves sideways) returning from the albacore grounds .....

The filler cap seemed to be the logical place where we got the water intrusion into the tank....the outboards pulling fuel create a suction effect ...any salt water hitting the fuel cap got sucked in........

You probably don’t want to hear this, Sue, but if you had the outboard running problems you mentioned, you might consider pumping the tank and having the inside polished. For sure, swap out the filter in BOTH your fuel water separator (external) and the internal one in your outboard

Wouldn’t be a bad idea to clean out the VST (vapor separating tank) in the outboard also

It might have been overkill but I had the tank pumped dry as mentioned, swabbed down with solvent, polished, and ALL fuel lines/water seperators replumbed and replaced

Oh, and a new filler cap...have not had the problem since

Excellent advice, sharphooks! We started at the tank - lots of crud came out, replaced fuel, fill and vent lines and cleaned fittings, replaced every filter, including in the VST and the injectors. End of problems!

 

[mbowers]

^^^^^^^^^ this^^^^^^

I had to pump 200 liters of fuel out of a contaminated tank last Fall. There was a blob of emusified crap in the plastic bowl of the fuel/water separator that had the consistency of mayonnaise. It killed one of my Suzuki outboards.

I started examining fuel lines, filler caps etc. I noticed the filler cap “O” ring had a flattened-out section surrounded by what appeared to be salt crystals. It was fitted to the top of the transom. The boat had just done a 6 hour run through snotty conditions (wind blowing waves sideways) returning from the albacore grounds .....

The filler cap seemed to be the logical place where we got the water intrusion into the tank....the outboards pulling fuel create a suction effect ...any salt water hitting the fuel cap got sucked in........

You probably don’t want to hear this, Sue, but if you had the outboard running problems you mentioned, you might consider pumping the tank and having the inside polished. For sure, swap out the filter in BOTH your fuel water separator (external) and the internal one in your outboard

Wouldn’t be a bad idea to clean out the VST (vapor separating tank) in the outboard also

It might have been overkill but I had the tank pumped dry as mentioned, swabbed down with solvent, polished, and ALL fuel lines/water seperators replumbed and replaced

Oh, and a new filler cap...have not had the problem since

Did you check the vent line for blockages? Air is literally 1000 times easier to suck in than water (try sucking on a straw with a pinhole leak) so if the vent is working well then the vacuum of the fuel system should not suck in much water because air easily comes in the vent.

But if the air vent is blocked or in my case the builder used a combo fill/vent and put it on a horizontal surface which meant the fill had to suck in seawater if a wave got on the deck.

 

[Sue]

Thanks for all the input. I did find the "o" ring on the filler cap damaged, so replaced that. Replaced both the large water separator filter, and the smaller gas filter on the outboard. Checked the vent line, no blockages. Bought a new portable tank and diverted the fuel line from it to the engine, with fresh gas. Still had the same problems. My research confirms what you are saying, maybe the VST or perhaps the fuel injectors are contaminated. Those jobs are above my skill level, so, boat back on the trailer and off to the dealer. Had an interesting trip through 2nd narrows to the boat launch in Deep Cove. Only able to make about 4 knots, so up extra early to avoid the max current.