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    Genset water priming.

    1997 Westerbeke 8.0
    I replaced the impeller on the raw water pump. Filled the pump with dish soap prior to install. Filled the intake hose with fresh water (I don't know if the water stays in the hose).
    I started the genset and let it run for 15 seconds; no exhaust water.
    Questions - How long can the genset run without discharge and not kill the rubber impeller?
    Will the genset prime itself?
    How to tell if the intake tube is holding water and not flowing through the pump?
    1997 Bayliner 3988

    #2
    My first admittedly silly question, did you open the through hull?
    P/C Pete
    Edmonds Yacht Club (Commodore 1993)
    1988 3818 "GLAUBEN
    Hino EH700 175 Onan MDKD Genset
    1980 Encounter Sunbridge "Misty Blue" (Sold)
    MMSI 367770440
    1972 Chevrolet Nova Frame off Resto-mod in the garage
    Boating on the Salish Sea since 1948

    Comment


      #3
      Thru hull is open. Water spouts about 6" above valve. I removed the exhaust tube and secured a fresh water hose. Water came out the exhaust port.
      I don't know how long to wait for the pump to pick up water; trying to avoid damaging the impeller.
      I also poured water down the intake hose but don't know if the water stays in the hose or flows to exhaust.
      Any ideas?
      1997 Bayliner 3988

      Comment


        #4
        Is the Impeller a spline or drift key?? The latter might be the issue?? You should not have to prime it,by your statement "6"above valve".did you rotate the impeller vanes to match the original?? they "should " rotate to the proper set even if installed wrong,however might be worth a look.....Good luck Brad
        Brad & Sharon
        Lady Jake
        1985 4550 EH 700TI /Twin Disc 502
        LaConner,Wa. (summer)
        2003 Scout CC 24' W/225 Yamaha
        kailua Kona,Hi (Winter)

        Comment


          #5
          Okay, water is getting to the impeller and Brad is having you double check the key way or flat on the shaft that spins the impeller. I’m not familiar with a Westerbeke, so, what turns the water pump shaft? And, is it turning? You didn’t say if you changed the impeller as routine maintenance or because there was an overheating issue, so I’m going for even sillier questions.
          P/C Pete
          Edmonds Yacht Club (Commodore 1993)
          1988 3818 "GLAUBEN
          Hino EH700 175 Onan MDKD Genset
          1980 Encounter Sunbridge "Misty Blue" (Sold)
          MMSI 367770440
          1972 Chevrolet Nova Frame off Resto-mod in the garage
          Boating on the Salish Sea since 1948

          Comment


            #6
            The grease you use to seat the impeller in the housing should provide a seal for priming and protection agsainst running dry for a bit.

            Start the generator and look at the sea strainer. On mine I can see some swirling. Also it can take a bit for water to start coming out.


            KEVIN SANDERS
            4788 LISAS WAY
            SEWARD, ALASKA

            Comment


              #7
              the 3988 Genset had the strainer mounted above the water line in some models and the hose configuration had quite a noticeable loop that trapped air in my boat (1997).
              I reconfigured it to remove the loop and remounted the strainer lower so water would spill out if the top was open. Even doing this the generator raw water intake at the water pump is still slightly above the water line of the vessel. The proper impeller is important , Johnson 09-810B, it has stiffer vanes than the Jabsco replacement. When changing the impeller I usually take the hose off at the water pump and lower it, with the seacock open, until water is flowing through with out any air. Then I close the seacock to trap the water, squirt dish detergent into the pump fitting and reattach the hose. Only then do I open the seacock and fire up the Genny. The first minute should have lots of foam in the water around the exhaust outlet to tell you that the water is going through and the sound should deaden as the water hits the muffler.
              "Adios Dinero"
              1997 3988 with new 330 Cummins
              Photo Credit: Whiskywizard

              Comment


                #8
                Thanks to all. I am going to try all suggestions until I get the unit running.
                1997 Bayliner 3988

                Comment


                  #9
                  Originally posted by The_Other_Gary View Post
                  the 3988 Genset had the strainer mounted above the water line in some models and the hose configuration had quite a noticeable loop that trapped air in my boat (1997).
                  I reconfigured it to remove the loop and remounted the strainer lower so water would spill out if the top was open. Even doing this the generator raw water intake at the water pump is still slightly above the water line of the vessel. The proper impeller is important , Johnson 09-810B, it has stiffer vanes than the Jabsco replacement. When changing the impeller I usually take the hose off at the water pump and lower it, with the seacock open, until water is flowing through with out any air. Then I close the seacock to trap the water, squirt dish detergent into the pump fitting and reattach the hose. Only then do I open the seacock and fire up the Genny. The first minute should have lots of foam in the water around the exhaust outlet to tell you that the water is going through and the sound should deaden as the water hits the muffler.
                  On our 4788 I replaced the seawater strainer with a Rartan unit that has no elbows on the inblet side.

                  I positioned it so that the top of the unit is just above the water line.

                  I think that is where you want a sea strainer, so that you can just barely remove the top without flooding.

                  KEVIN SANDERS
                  4788 LISAS WAY
                  SEWARD, ALASKA

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