How is water getting into my fuel?

[Skipsta]

I did an earlier post re asking you guys on how to syphon fuel out of my tank, reason being as my engine was barely running as water had gotten into the fuel. I bit the bullet and took it to Karee Marine at Rocklea. Along with my annual service, I asked the mechanic to fix my donk (obviously). It is a 2002 90hp Yammie 2 stroke on a 5.2 AMM Plate Centre Console.

They told me that the built in 120 litre fuel tank had a LOT of water in it. They said most likely from a bad batch of fuel at a servo. They cleaned out all three carbies and said that each carbie was clogged with about 2 teaspoons of white jelly substance each. They said they drained the tank, separated the fuel, then replaced the fuel. They returned it to me with the instructions of using a water separating funnel when I fill my tank and I put in a bottle of I think it was quicksilver dri-fuel to hopefully get rid of any residual water.

I took the boat for a couple of short runs. It was a little lumpy when idling and coughed every 30 seconds or so, but when I opened the throttle it ran well.

Problem is after about 1 1/2 hours of running, the revs dropped and it cut out. I went down to the fuel filter (water separator) and saw there was a heap of murky water in it. I drained this out and more came in.

Basically it fair stuffed up my fishing holiday in Hervey Bay

I am returning it to be looked at next week, but I want to know how this water is getting in I am keeping the tank full to lessen condensation. The boat is kept covered. I am using a fuel filter and water separating funnel. Can water get in by any other means? Like can it get in through the water pump in the engine and there be some sort of leak from this?

Can water get into the fuel lines or into the tank by some means that may be the fault of the boat manufacturer?

I know I'm doing the right things, but I'm starting to not trust the engine anymore, which is a sad thing.

[Billo]

Thats extremelly diasapointing ....and i can imagine your frustration

I find it hard to believe that the petrol you are putting in can really be that bad..

How is your tank set up in the boat ? where abouts is the air valve on the tank ? is there any chance water can pool around it ?

[Spaniard_King]

Skipsta,

There is only 3 possible ways water can get into ya fuel tank.

From the bowser
In Thru the filler cap... ie when washing down the boat or rain
In thru the tank breather again by rain,boat wash down or condensation (unlikely).

Its amazing how a small amount of damage to a filler cap will allow a large amounbt of water in. You state that you are using a fuel filter is it a water seperating filter with the glass bowl in the bottom

This is the best gettin around http://www.whitworths.com.au/main_it...AbsolutePage=1

Hope this helps

Garry

[Skipsta]

I guess the filler cap is a possibility, but it is only 6 months old, threads perfectly and has no signs of any damage. The breather is high up on the starboard side. The tank is set up under the console and is filled by a filler cap on the floor. I don't knoiw, maybe put some plumbers tape around the thread of the cap?

I'll put your thoughts to the mechanic. Cheers

[1810B]

Have a good look at the tank breathers as well. I had experience on 50 ft diesel powered boat with raised breathers for the tanks on deck, with 150mm covers , and near back of wheel house, sucking spray from cooling tank into fuel tanks. Took 18 months to find what was happening. Next owner, Bernie Cuthbertson from Tassie. most experienced seaman,had same problem with the boat until I caught up with him in Coffs Harbour and told him about it. If you have flexible lines in brather inlet line, put a fairly large loop into them, preferably where you can see the loop. If water(spray) is evident in bottom of loop, that will be easily seen.
regards 1810B

[CHRIS_aka_GWH]

the water is entering somewhere prior to the seperator filter - so the engine isn't at fault.

are the bilges dry.

an aquaintance just bought a brand new HH & the underfloor fuel tanks had been holed when they screwed fittings into the boat.

then there's the filler cap (is the o-ring or rubber seal present, if it isn't it won't seal & breather as said & are the clamps on the pipes tightened down - are the pipes not split / holed.

takes the fun away from a new toy really - best of luck.

[FNQCairns]

I have bought water with some fuel in it from a servo a few times, dont discount them as your source.

The servo owner must rub their hands with glee when every 3 months they calculate the bought 100,000L but pumped 105,000L.
I am sure they could filter their fuel first but where would the profit in that be!
They have cost me a fair few hundred over the years in extra maintenance and repairs. Still shirty >

When ethanol in fuel is forced upon us they will have an extra 5% to cram another 2% more water into.

What is a funnel that separates the water? With one of those I can get a refund each time I fill up [smiley=2thumbsup.gif]

cheers fnq

[billfisher]

It sounds like you are getting a lot of water. The water separating filter (with occasional draining) should easily cope with the small amount you will get from condensation. Is it an underfloor aluminium tank? If it is corroded and sitting in bilge water this could explain your problem.
I had to spend a lot on my car due to damage from water contamination in fuel and it could only have come from the service station. Did you buy your fuel from the same servo when the problem recurred?

[lil_boatie]

This wont really answer your question, but at work the other day a guy brought in his boat to get the under floor fuel tank removed because he had the same problem as Skipsta, now as i was talking to him he was telling me about it could be the under floor or a external but he had not checked the external yet, he made us get the grinder out and cut the floor up, Dont know what happened after that he got the s#!ts and left.He dont like that he got me, doing work exp, fix his boat.

Thanks.

[Dodge41]

skipsta

Many tanks have the pickup pipe mounted above the bottom of the tank so that water and crap will settle and lay there while you get the clean fuel above.
If the tank drain was not a seperate bung right on the bottom [like your car sump] you may still have contaminated fuel in there as I doubt you could syphon empty.
If thats the case when your boat rocks the sediment will go into suspension and continue to enter your feed pipe.
Solved this on one of my former boats the following way way, it also checked for tank pinholes
Drained the fuel as much as possible, plugged the breather, plugged the feed line, then insertd an airline in the filler which was also stuffed with rag.
We then applied enough air to give light pressure in the tank; if you have any leaks anywhere you will hear air escaping, we increased the pressure and then released the plug at the feed line which was the lowest, and pressure blew out a lot of the residue. We repeated many times, until it was clear.
The curl in the breather pipe is a must as mentioned in an earlier post, as is the cap washer.
The water trap will have to empty many times till you best the problem, but normally they have a plastic tap, so just keep going until it stops.
Only one other thought is the breather in a spray of mist when you're at speed?

Like others have said it's not a motor problem. [I'm no mechanic though]

Goodluck Richo

[Burley_Boy]

My tanks are 22L portable units and I have no water separator. Had major problems (500ml water in fuel!!) until I started filling the tanks full after each trip, no problems since.
Once water in fuel I wouldn't waste my time with additives to get rid of it, never worked for me, just my situation won't say its yours, good luck.

[fishman7]

hi skipsta
could you bypass your tank?get a 20l all so tank and run that staight to the motor and then if the motor works ok you know that it is somethink to do with the tank in the floor.
cheers
danny

[Brooksy]

Skipsta where are your breathers for the tank situated?
I have seen several now mounted on the side of the hull not the stern. When these boats were run in a bit of sea water was forced into the breathers. Once the breathers were shifted problem was solved.

Steve

[gunna]

Is there any chance they didn't COMPLETELY drain the tank when they worked on it. Maybe left water in it ??

[2iar]

hi skipsta
could you bypass your tank?get a 20l all so tank and run that staight to the motor and then if the motor works ok you know that it is somethink to do with the tank in the floor.
cheers
danny

Hi Skipsta,

I've got a couple of fuel tanks with Yammie fittings if you want to borrow them and give this a try. At least you'll be able to narrow down where the problem is.

Mike