Water in fuel tank-next move?

[halcion]

My boat yard tells me that I have water in my fuel tanks (which hold 155 and 150 gallons each). He came to this conclusion because the water fuel separator was full of water when he changed it in the fall. His suggestion is to remove the water and clean the tanks (not sure how this is done).
The cost is 3 hours at 130 per hour, plus the cost of disposing of the water. He does not know how much water is in the tanks. I just bought this 2006 Marlin in May 2011 with 150 hrs.
Any suggestions on whether I should just change the separator a few times next year, or just let the yard do the job?
Second question is what is the most common reason water gets in the tanks and what should I do to prevent this going forward.
Thanks

 

[gerrys]

I would just change the separator and filter and keep an eye on it. You may have just picked up some condensation or a slug of water from a fill-up. You might also look under the inspection hatch at the fuel sender cover plate to make sure everything is tight and in order there. The only reason to clean the tank would be sludge, algae or other contaminant - not water.
It sounds like your mechanic needs some work.

 

[cgmiller]

That sounds out like a lot of water for a 2006 boat. Maybe the orings on the fuel fill caps are loose and letting in rain water, usual source is condensation from leaving tanks near empty. You can also get it from a contaminated fuel source like old storage tanks in the place where you or the previous owner was buying fuel. Are there any guys in your are that offer fuel tank cleaning services? I had the tanks in my last Shamrock done and the guy came to my dock and flushed the tanks with the fuel in them and filtered and cleaned the fuel through his multifilter set up. You may be better off to pony up and pay to have the tanks cleaned then rish losing part of your season fighting with engine problems due to water in the fuel....

 

[RAINMAKER]

It does sound like the mech. needs some work. Read the recent post on here about how to get the water outa your tanks. Its really easy and shouldn't cost you a small fortune to do it yourself.

 

[aa331]

I've been told water gets in most of the time via the filler cap, the gasket gets old and leaks, so just replace it. Also the fuel sender on the gas tank has a gasket, no big deal at all to get to and replace the gasket. Last thing I could think of is the gas station you're using has water in the gas.

If there's that much water and it separated from the gas, you could get the water out via siphon. Lift the front of the boat as much as possible on the trailer, take the fuel sender off, use a hose and siphon the water out of the bottom rear of the tank.

I'd put in Racors w clear bowls so you can easily watch the water level, and can drain the water without taking the filter out. Run the fuel tanks as empty as possible to make sure you get as much of it out as you can. Take a couple of spare filters and a portable gas tank with clean fresh fuel just in case. I run Racors 2 micron (S3220SUL) and have no problems.

Good luck.

 

[seasick]

What you didn't say is if you know when the separators were last changed. If they have been in service for a long time, the water may not be as big an issue as the case where they have been in service for a few hours.
Forget about the condensation theories. If you have a lot of water, 99.9% of the time it is from intrusion: Bad filler seals (o-rings) or a vent issue. Most likely it is a filler issue.
I would change the separator and run for a bit ( hopefully you won't get stranded) and then remove the separator/filter and drain into a glass jar. Let the mixture sit for several hours and see if water settles to the bottom. If you don't see any, repeat over time. Water may be in the bottom of the tank below the pickup tube. To remove, you need to go in via the sender hole. If the tanks are fairly full, this can be dangerous since fuel can leak out of the sender access hole.
Draining the tank may be needed and you don't want to do that yourself but if it is water intrussion ( as opposed to a bad load of gas), you will have the water again unless you fix the intrusion problem first. That would mean you wasted a lot of money.
Also depending on your motor models, you can check the engine mounted filter for water. If it is there, you really need to find the cause.

 

[NikM820]

$130/hr, ouch! 1st off see if you can get a mobile guy for less. I'm not sure where you are but around here $80/hr is our labor rate. For that money I second throwing on some racors and periodically checking your glass bowls. The water will settle at the bottom of the bowl and you can just drain it off. Although another option is put an ad on Craigslist for 305 gallons of free/cheap gas, they just have to store it and pay to have it pumped. There are a couple ways to get the fuel out, make sure if you do put new racors on they don't pull all that old fuel through them. I had to get rid of a little over 200 gallons and an owner of a lawn service company showed up with 5 of those big blue barrels. I had my mechanic pump the gas out into his barrels. My mechanic charged me a few bucks but the guy getting the gas was more than willing to pay that, and I knew the gas was getting out appropriately. If its a low percentage of water in the fuel they can add ethanol to the gas (I know sounds crazy) which will dissolve the water into the fuel. Fine for lawn mowers and cars but not cool for our yamahas. All in all it depends on the cost vs hassel. Although the points listed above about intrusion are good and should be looked into but having gone through this I would be willing to bet, you had some ethanol gas sitting for a long time or those fuel filters are old.
Good luck
Nick