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Tracking down misfire. Droplets on carb butterfly?-gctid410162

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    Tracking down misfire. Droplets on carb butterfly?-gctid410162

    Hi Folks,

    I am tracking down a soft misfire probably caused by my laziness in not servicing the engine often enough. I am on the case with the laziness but the misfire isn't so easy.

    I noticed that when I took the flame arrestor off, and moved the choke flap out of the way, that there were water droplets on the back of the throttle butterflies (Mercarb 2). The only water sources that I can think of are water in the fuel and condensation.

    Is anyone going to say "It is just condensation; you get that all the time" or "that is water in the fuel"?

    Any ideas?

    I have now changed the water separating fuel filters (I have one in front of a fuel sensor and there is one next to the 5.0L Vortec's electrical fuel pump). I wont get a chance to try the boat again for a good few days and it would have had a shed load of parts replaced at the same time. So, I won't really be able to tell easily whether the droplets were a good sign of water in the fuel. It would be great to have an indicator of water in the fuel if that is what the droplets provide.

    Also, the fuel that came out of the filters was poured into a glass measuring jug. It came out clear with no sign of droplets. After a few minutes standing it turned cloudy. Again, can anyone suggest what is going on here? I have never seen what hapepns when water gets into petrol.
    Terry (Retired Diving Instructor and Part Time IT Consultant)
    1998 Bayliner 2452. 5.7l V8 - Edelbrock 1409 4bbl - Alpha1Gen2 - Solent UK.
    MMSI 235061726

    #2
    Misfire is usually ignition relation. Make sure the timing is right on and check you advance.

    Comment


      #3
      Distributor cap
      2007 Discovery 246
      300mpi BIII
      Welcome island Lake Superior

      Comment


        #4
        I haven't got time to mess around so the majority of the ignition components will get swapped this weekend (cap, rotor, coil). Leads and plugs are new but I'll change out the plugs again as whatever produced the misfire may have affected them.

        I am still troubled by the droplets though. When she is running right, I'll whip the arrestor off and see if there are still droplets there. That way I'll know if they are a sign of problems on the way.

        Many thanks.
        Terry (Retired Diving Instructor and Part Time IT Consultant)
        1998 Bayliner 2452. 5.7l V8 - Edelbrock 1409 4bbl - Alpha1Gen2 - Solent UK.
        MMSI 235061726

        Comment


          #5
          Hi, if you give the butterflys a good clean and after overnight check them the next day and if there is any moisture then it must be condensation. My carb is off the boat at the moment but i will check and see if i am getting the same thing.

          Regards

          Comment


            #6
            spike2450 wrote:
            Hi, if you give the butterflys a good clean and after overnight check them the next day and if there is any moisture then it must be condensation. My carb is off the boat at the moment but i will check and see if i am getting the same thing.

            Regards
            Hi Dave,

            Sounds a good ploy.

            I did the clean up a few days ago when I changed the fuel filters (they were rusted solid off course even with a ship-load of grease put on them when done up).

            Many thanks.

            Terry
            Terry (Retired Diving Instructor and Part Time IT Consultant)
            1998 Bayliner 2452. 5.7l V8 - Edelbrock 1409 4bbl - Alpha1Gen2 - Solent UK.
            MMSI 235061726

            Comment


              #7
              In the past i've purchased just about every filter tool, i had to drive a screwdriver through my last fuel filter, the working area is so limited /crap to get at them. Why bayliner didn't put a remote oil filter on every 2452 is beyond me!!!!!

              Even little things like checking the spark plugs or checking compression is just about impossible without dropping the exhausts.

              Oops i'm ranting but still love me boat, ( but would swap it without hesitation for a newer model with a raised floor ).

              Comment


                #8
                The Parker/RACOR fuel filter system will pretty much solve any water issues.



                These are now sold under the names of Sierra, GLM and also Mallory.

                They can be installed as a "re-tro fit" kit to your existing fuel filter base (you must know the thread size/pitch), or you can buy the complete kit w/ the base unit.

                You'll need one only, and installed right after your fuel tank pick up fitting.

                .
                [CENTER] Rick E. Portland, Oregon
                2850 Bounty Sedan Flybridge model
                Twin 270 HP 5.7's w/ Closed Cooling
                Volvo Penta DuoProp Drives
                Kohler 4 CZ Gen Set

                Comment


                  #9
                  2850Bounty wrote:
                  The Parker/RACOR fuel filter system will pretty much solve any water issues.



                  These are now sold under the names of Sierra, GLM and also Mallory.

                  They can be installed as a "re-tro fit" kit to your existing fuel filter base (you must know the thread size/pitch), or you can buy the complete kit w/ the base unit.

                  You'll need one only, and installed right after your fuel tank pick up fitting.

                  .
                  Nice.
                  Terry (Retired Diving Instructor and Part Time IT Consultant)
                  1998 Bayliner 2452. 5.7l V8 - Edelbrock 1409 4bbl - Alpha1Gen2 - Solent UK.
                  MMSI 235061726

                  Comment

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