Water in fuel

[clayprystash]

I have a Suzuki 115 4 stroke with an ongoing problem of water in the fuel. This has been going on for several years and resulted in thousands of dollars in repairs. I have a fuel/water separator attached and it seems to be doing its job but after running the boat after having the fuel pump and pressure regulator replaced that were completely corroded I poured out a lot of water from the filter. Does anyone have any idea where the water is coming from?

[Harper]

Using ethanol gas, are you? Ethanol is hygroscopic, meaning that it absorbs water. In that we have open tanks (vented to the atmosphere) the ethanol will absorb water from the atmosphere over time. If it absorbs too much water, it can not longer hold that water, and phase separation occurs. This is when the water separates from the ethanol/gas blend and being heavier, settles to the bottom of the tank.....right where your fuel pickup is.

There are several remedies, the most effective one being to use non-ethanol gas, if you can get it. If you're in the USA or Canada, you can use this website to locate some dealers near you who sell non-ethanol gas. Ethanol-free gas stations in the U.S. and Canada

If you can't find the non-ethanol good stuff, then try putting into the tank only what you figure you'll use in a day. Not really a good option, of course, for obvious reasons. But the main thing is when/if you store your boat in the winter, or go long periods between uses, either empty the tank, or have it completely full. Never store your boat for long periods of time with a half-full tank. You're just asking for trouble.

Now if you just happen to be already using non-ethanol gas, you have a bigger problem. You're getting water in the tank somehow. That's a whole 'nother ball game.

[Moonlighter]

There are only a limited number of ways for water to get into the fuel tank. You need to systematically eliminate them. Also, since you obviously still have water in the tank now, it would be highly recommended to drain the tank entirely and ensure all water is gotten out.

1. Contaminated fuel from your gas station. Get yourself a "Mr Funnel" water separating fuel funnel and add the first few gallons of fuel thru the funnel, this will show up nay water in the fuel as it is added. Or, take a large glass jar and put some gas in it as you start to fill. Allow to settle and look for a layer of water at the bottom.

2. Leaking in thru fuel filler cap. Check O rings and make sure all are good and filler cap seals up properly.

3. Water accumulating on top of fuel tank below floor. Thee have been cases where water gets onto the top of the tank (possibly by condensation, or thru a inspection hatch) and pools around the tank sender unit connection or take off fittings, and leaks slowly into the tank due to bad gaskets on those fittings. Check and replace gasket if required. Find out how water is getting onto top of tank and rectify.

4. Condensation in the tank. Try to refill the tank full before storing the boat. You may want to use fuel stabiliser if the boat is not used regularly. A full tank will not get condensation inside. Given the amount of water you seem to be getting, it would be less likely that condensation is the cause.

5. Thru the tank breather vent. We saw a major case of this recently in our fishing club - the breather vent fitting was on the starboard side of the boat and was catching water spray and drawing it into the tank as the boat was underway.

Remember when you are at speed, the tank vent will be "inhaling" air to replace fuel that the engine is using from the tank. Make sure the vent fitting is not placed in a position that could allow spray to be sucked in, or that might allow rain or other water to get drawn into the tank.

In the case of our Club member, the vent was repositioned to face rearwards, and a shield put over it, and, further, a separator bottle was added inside the boat to catch any water before it could get into the tank - like a catch can in a race car. The breather line thus goes from the fitting on the side of the boat, into the top of the catch can. Any water in the hose drops to the bottom of the catch can. A second length of hose then goes from the top of the catch can to the tank. So only air can be drawn in. Using a transparent plastic can lets you see any water that has got in, and the can can be emptied.

6. A cracked or pitted and holed fuel tank is the final possibility. Water in the bilge can get in, or, if the tank is set in foam, if the foam has become water saturated, it can get in from there. Although usually, you would be smelling some fuel smell in the bilges too. The only solution is a new tank - big job.

Remember that a water separating filter is only effective until it is full of water, then there is nowhere for the water to go except to your motor. Check it regularly.

See how you go looking at the first 5 possible sources. They are relatively easy to check.

[clayprystash]

Water in fuel

Want to thank Harper and Moonlighter for all their input. I guess I should have elaborated more on the history of the problem. The boat is a 2003 Fishmaster and the motor is an '03 also. The problem started 5 or 6 years ago and I've been chasing it ever since. Thought we had it licked with replacing the fuel pump and pressure regulator(again). They were severely corroded. First trip out it ran fine until we were coming back down a channel when it would severely bog down in choppy water. No problem in smooth water. It didn't like anything above 2400 rpm or so. Was windy that day so had a lot of choppy water. My fishing partner pointed out the primer bulb was sucked completely flat so figured there was an obstruction somewhere either in the pickup or the anti-siphon valve(it expanded to normal only when the motor was shut down). Couple weeks later I took the boat to his place and we pulled the valve. It was full of junk, mostly small rubber pieces(that did not give me a warm fuzzy feeling). We forced air through the line and also knocked the ball and spring out of the valve. Thought that would cure the problem. Took it to a local lake the next week and it ran great with one exception. Was running it about 5000 rpm and the rpms suddenly dropped for about a second. After that it ran fine again.

Regarding the suggestions, I have been using fuel stabilizer for quite a few years since the problem started. I check the separator after each trip(the last one was when the filter had almost half water in it and that was the worst ever). I don't smell any fumes in the bilge. The breather vent is positioned rearward so don't think that's the prob. The filler cap o-rings look ok but I might replace them anyway. If it's the tank, I can't go there. Too expensive. This has already cost a small fortune. If the final determination is a faulty tank I'll just abandon it and install a 10 gallon aux tank.

Thanks again for all the suggestions and sorry for the rambling.