1956 Evinrude Big Twin #25022 water pump

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  • January 4, 2020 at 10:12 pm #190974
    bobw
    Participant

      US Member

      There was an article on this topic on page 51 of the July 2018 Antique Outboarder on this bleed hole issue. Frank, how does this work when the length of the water tube rubber grommet blocks the outside hole?

      Bob

      1937 Champion D2C Deluxe Lite Twin
      1954 Johnson CD-11
      1957 Evinrude Fastwin 18
      1958 Johnson QD-19
      1958 Johnson FD-12
      1959 Johnson QD-20

      “Every 20 minute job is only a broken bolt away from a 3-day project.”
      "Every time you remove a broken or seized bolt an angel gets his wings."

      January 4, 2020 at 10:54 pm #190992
      dave-bernard
      Participant

        US Member

        bucket test it before you install the lower unit.

        January 5, 2020 at 12:36 am #190996
        garry-in-michigan
        Participant

          Lifetime Member

          I had thought the hole was drilled at an angle so the outside was blocked while the inside wasn’t. Has the upper water tube grommet been pushed out of place so not all the water going up the water tube makes it to the powerhead?

          Strange – The worry I heard the most was that the motor stopped pumping at high speed. What actually happened is the underwater exhaust outlet was so efficient that a light boat at high speed developed a vacuum in the exhaust housing that sucked the water discharge into the housing.

          January 5, 2020 at 3:57 am #191004
          frankr
          Participant

            US Member
            bobw wrote:

            There was an article on this topic on page 51 of the July 2018 Antique Outboarder on this bleed hole issue. Frank, how does this work when the length of the water tube rubber grommet blocks the outside hole?

            The hole is drilled at an angle, from the pump outlet area, through to the well in the center. Thus, water flows into the well, providing a water seal to keep air/exhaust from entering the pump through the drive shaft hole. Yes, the grommet blocks the outer end of the hole, and no water squirts out there. What’s important is that the angled hole be open between the pump outlet area and center well.

            BTW, the water intake screen is positioned so that at higher speeds, and in gear, the prop force-feeds the intake screen. In neutral, the prop is not feeding the intake screen, so you are depending on pump suction to draw water in. The pump is acting as a positive-displacement pump at slow speeds, so it has a bit of suction—but not much. At high speeds, the pump vanes flex back and the pump acts as a centrifugal pump, aided by the mentioned force-feed.

            Clear as mud??

            January 5, 2020 at 11:09 am #191022
            bobw
            Participant

              US Member

              Yes, that is clear to me as I always knew the water tube grommet blocks the outer hole on the pump outlet. What made it confusing was the article in the Outboarder only seems to describes the holes drilled at an angle through the pump outlet area and the article says “both holes must be free of any blockage to have the pump operate as intended”. Should be the inner hole in the outlet area and the hole in pump well need to be open.

              Bob

              1937 Champion D2C Deluxe Lite Twin
              1954 Johnson CD-11
              1957 Evinrude Fastwin 18
              1958 Johnson QD-19
              1958 Johnson FD-12
              1959 Johnson QD-20

              “Every 20 minute job is only a broken bolt away from a 3-day project.”
              "Every time you remove a broken or seized bolt an angel gets his wings."

              January 5, 2020 at 1:40 pm #191045
              frankr
              Participant

                US Member

                I see where the confusion comes from. Don’t over think it. When you get it apart and in your hand, it will be obvious. Remove the rubber grommet and stick a drill or whatever through the angled hole. It will appear in the well and all is good. Yes, the re-installed grommet will block the outermost hole, but not the hole into the well..

                January 5, 2020 at 3:06 pm #191055
                bobw
                Participant

                  US Member

                  I’ve always seen the angled hole and it seemed obvious to me how it works. The wording used in the Outboarder article just didn’t seem to make sense.

                  Bob

                  1937 Champion D2C Deluxe Lite Twin
                  1954 Johnson CD-11
                  1957 Evinrude Fastwin 18
                  1958 Johnson QD-19
                  1958 Johnson FD-12
                  1959 Johnson QD-20

                  “Every 20 minute job is only a broken bolt away from a 3-day project.”
                  "Every time you remove a broken or seized bolt an angel gets his wings."

                  January 5, 2020 at 4:53 pm #191060
                  Geer Pyron
                  Participant

                    Thanks for all the input.
                    All the holes are clear. I tend to be a better parts cleaner than anything else.
                    Some motors call for a gasket below wear plate. Some not. We have not been installing one on this motor, but that must be the issue.
                    Thanks again.
                    And Frankr , if you’re still in FL, will you be going to the Lake Hamilton swap meet?
                    Hope to be able to meet you in person if so.
                    That actually applies to any of the guys in FL who have been helping me out so much!
                    Geer

                    JMGP

                    January 5, 2020 at 5:28 pm #191064
                    Geer Pyron
                    Participant

                      Ahhhhhh!
                      I just checked the manual and the Johnson equivalent (?), RD 19, does not call for a gasket below the wear plate.
                      We’ll have to look for cracks now.
                      G

                      JMGP

                      January 5, 2020 at 5:45 pm #191070
                      bobw
                      Participant

                        US Member

                        Without a gasket, have you installed a sealer to the top of the gearcase so the impeller plate is sealed properly?

                        Bob

                        1937 Champion D2C Deluxe Lite Twin
                        1954 Johnson CD-11
                        1957 Evinrude Fastwin 18
                        1958 Johnson QD-19
                        1958 Johnson FD-12
                        1959 Johnson QD-20

                        “Every 20 minute job is only a broken bolt away from a 3-day project.”
                        "Every time you remove a broken or seized bolt an angel gets his wings."

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