• If this is your first visit to the iboats.com Boating Forums, be sure to check out the FAQ. To post a question or comment, begin by signing up. To start viewing messages, select the forum that you want to visit from the selection below.
  • ALL iboats Forum Members and Guests:
    To show our appreciation for your participation in the Forums, we're offering an exclusive Forums-only discount good for an additional 5% off your iboats.com order for a limited time.
    To redeem, simply call our Customer Service Team at 800-914-1123 (Open M-F, 9am - 8pm Eastern Time) and mention the Forums 5% off discount. Offer excludes engines, trolling motors, and electronics.

Announcement

Announcement Module
Collapse
No announcement yet.

Ethanol Fuel Seperation Problems

Page Title Module
Move Remove Collapse
X
Conversation Detail Module
Collapse
  • Filter
  • Time
  • Show
Clear All
new posts


  • Ethanol Fuel Seperation Problems

    I suspect that I have an ethanol seperation problem. My engine dies under hard acceleration so I drained the carb bowl, collected the fuel into a glass jar. There is definatley two seperate layers in the fuel. After reading several posts online, I suspect ethanol seperation. How can this be confirmed? How can this be remedied? Will fuel treatment or fuel drier break the fuel up so it can be burned? Any advice is appreciated. Thanks a million.


  • #2
    Re: Ethanol Fuel Seperation Problems

    Just about any old fuel will go bad.

    Install a fuel/water separator.

    Usually people drain older/bad fuel and use it to mow their lawns.
    This is a great link to boat specifications http://boatspecs.iboats.com/
    Please, shop iboats first!!

    Comment



    • #3
      Re: Ethanol Fuel Seperation Problems

      The bottom "layer" you see is water (or mostly water). As already mentioned get rid of the bad fuel, install a fuel/water separator, and start adding fuel treatment every time you buy fuel.
      Checkmate Rebuild: http://forums.iboats.com/forum/boat-...eckmate-eluder

      “Anti-intellectualism has been a constant thread winding its way through our political and cultural life, nurtured by the false notion that democracy means that 'my ignorance is just as good as your knowledge.'”

      ― Isaac Asimov

      Comment



      • #4
        Re: Ethanol Fuel Seperation Problems

        I'm curious about how old your fuel is. There doesnt seem to be a good answer on what the time frame is about when water seperation occurs in ethanol fuel. Right now, I have marine gas with val-tech that is 3 weeks old. Have about a half tank now and when I first filled tank I put stabil in (red stuff). The remaining gas will be burned on Saturday.
        08 larson 180 sport 4.3 alpha one
        06 chevy trailblazer
        10 dodge challenger

        Comment



        • #5
          Re: Ethanol Fuel Seperation Problems

          You prevent separation by using the fuel before it separates. You protect the fuel by using a fuel system treatment of which there are many (Stabil and SeaFoam to name just two). Adding a water separating fuel filter is very important.

          Comment



          • #6
            Re: Ethanol Fuel Seperation Problems

            Th fuel will not separate unless there is water in there also. Water can get in obviously by a leak, bad supply, or from condensation forming on the interior of the tank. You can prevent this condensation by keeping the fuel tank full. This keeps air out of the tank. Humid moisture laden air that cools is the source of the condensation.
            1988 Sea Ray Seville 16 BRO w/1997 Mariner 115
            My build thread
            My upholstery thread

            Comment



            • #7
              Re: Ethanol Fuel Seperation Problems

              If its phase separation its a mixture of water and alcohol. Throw the concoction in a bucket of water. If it's phase the fluid will turn white when it comes in contact with the water.

              Gasoline and alcohol will not separate over time and you can not condensate enough moisture out of the air to cause phase. The only way separation occurs is if you have free water in your tank. You left the cap off, water got in thru the vent or you where “dosed” at a filling station.

              Contrary to what the additive salesmen wants you to believe, there is no additive that will prevent phase and there is no additive to repair it. If you have a large quantity of free water in the tank the only solution is to remove it. You can drain the tank, or siphon the water off the bottom of the tank if you have a large tank, but you need to get the free water out of the tank if you want to mitigate the problem correctly.
              Grady White 226
              200 Evinrude Ocean Pro
              Evinrude Renegade Offshore Prop

              Furuno FCV 587 Sounder
              Garmin 4208 Multifunction Display
              ICOM M504A VHF
              Shakespeare Galaxy 5225-XT Antennas

              Comment



              • #8
                Re: Ethanol Fuel Seperation Problems

                I can not believe how lucky I have it here in SW MO. Several gas stations around here have ethanol free premium, 20 to 30 cents more than premium blended w ethanol. Well worth the cost. Run it in all my small engines, especially the 2 strokes.

                Comment



                • #9
                  Re: Ethanol Fuel Seperation Problems

                  I filled my tank with high octane fuel last November and added the recomended amount of fuel stabilizer. The boat was dry docked and stored indoors. I am certain there is no chance that water introduced to the fuel system. I ran it for the first time on July 2nd and encountered poor performance above 25mph. Like I mentioned, the boat starts right up and idles however will not run at higher speeds. The gas does not stink like it is bad. All I know is I will not purchase any more of that brand of fuel.

                  Comment



                  • #10
                    Re: Ethanol Fuel Seperation Problems

                    Originally posted by dingbat View Post
                    ... and you can not condensate enough moisture out of the air to cause phase. ...
                    I disagree. It depends on the venting of the tank and the amount of air space in the tank. A vented tank with a lot of air space and not a lot of fuel in it can condense enough water to cause separation. It doesn't happen overnight, but if it has been sitting a long time it can and does happen.
                    1988 Sea Ray Seville 16 BRO w/1997 Mariner 115
                    My build thread
                    My upholstery thread

                    Comment



                    • #11
                      Re: Ethanol Fuel Seperation Problems

                      If you start good, idle good and run good below 25 and not above 25 mph, I think you need to look at something besides bad fuel, bad fuel should give performance problems at all operating points. You may have low fuel pressure, fuel filter stopped up, if you had that much water in fuel you probably would not start.
                      http://www.facebook.com/iloveboating


                      http://myboat.wikispaces.com/
                      2004 Sea Ray 185 Sport, 4.3L,190, Alpha
                      1994 GMC 4X4 1500, 5.7L

                      Comment



                      • #12
                        Re: Ethanol Fuel Seperation Problems

                        Litewin - try a small fix first like changing your water seperator and draining the gas and replacing with fresh gas. Becasue I am interested in this issue I have seen posts where guys hook up a small 6 gallon portable fuel tank to start diagnosing. But, the easiest fix may be the water seperator?
                        08 larson 180 sport 4.3 alpha one
                        06 chevy trailblazer
                        10 dodge challenger

                        Comment



                        • #13
                          Re: Ethanol Fuel Seperation Problems

                          Originally posted by 109jb View Post
                          I disagree. It depends on the venting of the tank and the amount of air space in the tank. A vented tank with a lot of air space and not a lot of fuel in it can condense enough water to cause separation. It doesn't happen overnight, but if it has been sitting a long time it can and does happen.
                          It is highly unlikely according to these two EPA memos and numerous other studies I've read.

                          Since the solubility of water in both gasoline and air decreases with a decrease in temperature, water can enter a fuel system through condensation when the atmospheric temperature changes. For example, assume a tank containing conventional gasoline contains only one gallon of fuel. Assume also that it is closed while the outside temperature is 100 degrees F with a relative humidity of 100 percent. If this tank is left sealed and the temperature drops to 40 degrees F, water will likely condense on the inside of the tank, and dissolve in the fuel. In order for enough water to condense from the air to cause gasoline-water phase separation, however, there must be approximately 200 gallons of air per gallon of fuel over this temperature drop (100 to 40 degrees). Since oxygenated fuels can hold even more water than conventional gasoline, it is even more unlikely that enough water will condense from the air to cause gasoline-water phase separation.

                          Water, in the form of water vapor, can dissolve in gasoline. The more humid the air, the faster the water vapor will dissolve in the gasoline. Due to chemical equilibrium, however, assuming a constant temperature, phase separation will never occur if the only source of water is from the air. Only enough water to saturate the fuel can enter the system, and no more. Water vapor, however, dissolves in gasoline very slowly, even at very high humidity. For example, at a constant temperature of 100 degrees F and relative humidity of 100%, it would take well over 200 days to saturate one gallon of gasoline in an open gasoline can (assuming the only source of water is water vapor from the air). Water absorption from the air is far slower at lower temperatures and humidity. (At a temperature of 70 degrees and relative humidity of 70%, it would take over two years to saturate one gallon of conventional gasoline in the same gasoline can.) Again, oxygenated gasoline can hold more water than conventional gasoline, and would therefore take much longer to saturate with water.
                          http://www.epa.gov/oms/regs/fuels/rfg/waterphs.pdf

                          Some manufacturers have expressed concern that ethanol-blended gasolines might absorb water vapor from the atmosphere, leading to phase separation. Such problems are of greatest concern for engines with open-vented fuel tanks that are operated in humid environments, such as marine engines. However, evidence for this phenomenon occurring is limited at best. States with extensive ethanol programs, such as Minnesota, have not reported problems with phase separation due to absorption of water from the atmosphere.

                          Limited testing with ethanol blends suggests that the rate of water absorption from the atmosphere is very slow; it requires several months for open-vented marine fuel tanks to accumulate sufficient water to make phase separation possible, and another source of water is needed before separation will actually occur. Of far greater concern is the accidental introduction of water, by splash or spray, during fueling or the presence of water in the fuel
                          tank prior to the addition of ethanol-blended gasolines.
                          http://www.epa.gov/oms/regs/fuels/ostp-3.pdf
                          Grady White 226
                          200 Evinrude Ocean Pro
                          Evinrude Renegade Offshore Prop

                          Furuno FCV 587 Sounder
                          Garmin 4208 Multifunction Display
                          ICOM M504A VHF
                          Shakespeare Galaxy 5225-XT Antennas

                          Comment



                          • #14
                            Re: Ethanol Fuel Seperation Problems

                            If you don't let any water into your tank then you won't get any condensation in it.

                            Comment



                            • #15
                              Re: Ethanol Fuel Seperation Problems

                              The gas sample is definitely seperated with milky colored water. I will siphon the fuel out this weekend and install a water separator. (Filter type with a clear water trap on the bottom)

                              All of the fuel system components are new including a complete carb rebuild and the system function was confirmed to be ok.

                              My system has two fuel pumps, an electric fuel pump serves as a booster to the main mechanical fuel pump on the engine. So no problems with fuel pressure. (8psi at the fuel inlet to the carb)

                              The boat will idle ok but however will not operate when fuel demand is high. Keep in mind the main jets and power valve are located at the bottom of the fuel bowl where the water settles. So when fuel demand is high, water is ingested instead of gas.

                              I will make the updates, test the boat and let everyone know if there is a happy ending.

                              Thanks for all of the great feedback.

                              Comment

                              Working...
                              X