Home Forum Ask A Member 1941 Neptune Muncie Magneto

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  • #237516
    NeptuneMadness
    Participant

      Hey friends, I tried to start a fully rebuilt 41′ Neptune this weekend with no luck, few little odds and ends to go back over. looking over the magneto/flywheel one thing really stuck out

      magneto

      Should there be 3 of those plates inside? you can see at the tip of the pen, it looks like something was once glued on their. I do spark, you can see the sparkplug light when you spin the motor. but that caught my attention. Thank you

      #237524
      Buccaneer
      Participant

        US Member

        Just the coating coming off. You should keep a “keeper” across those
        magnets when the flywheel is off for any length of time.

        Prepare to be boarded!

        #237541
        Bob Wight
        Participant

          US Member

          Just the coating coming off. You should keep a “keeper” across those
          magnets when the flywheel is off for any length of time.

          I’ve read before that a keeper of some sort should be placed across the magnet poles when the flywheel is removed for a length of time. Exactly how does that prevent loss of magnetism? Guess I should install something on my ’37 Champion flywheel while I’m still working on the motor restoration and the flywheel is just sitting on the bench.

          Bob

          1937 Champion D2C Deluxe Lite Twin
          1954 Johnson CD-11
          1955 Johnson QD-16
          1957 Evinrude Fastwin 18
          1957 Evinrude 3022
          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."

          #237581
          Buccaneer
          Participant

            US Member

            Just the coating coming off. You should keep a “keeper” across those
            magnets when the flywheel is off for any length of time.

            I’ve read before that a keeper of some sort should be placed across the magnet poles when the flywheel is removed for a length of time. Exactly how does that prevent loss of magnetism? Guess I should install something on my ’37 Champion flywheel while I’m still working on the motor restoration and the flywheel is just sitting on the bench.

            That’s a good question, but I have no answer!

            Prepare to be boarded!

            #237631
            crosbyman
            Participant

              Canada Member

              U shape magnets come with a keeper bar…. time to google… 🙂

              Magnetic Circuit
              A magnetic field holds its strength best when the entire magnetic loop, or circuit, passes through a ferromagnetic metal at all points. A horseshoe magnet has an air gap between its two poles; the keeper closes this gap. A bar magnet, left by itself, will lose its strength over several months. Though a bar magnet has no “keeper,” if you lay two bars side by side, with the north pole of one touching the south pole of the other, they form a magnetic loop in iron and preserve the strength of both magnets.

              Joining AOMCI has priviledges 🙂

              • This reply was modified 4 years, 6 months ago by crosbyman.
              1 user thanked author for this post.
              #237639
              Bob Wight
              Participant

                US Member

                U shape magnets come with a keeper bar…. time to google… 🙂

                Magnetic Circuit
                A magnetic field holds its strength best when the entire magnetic loop, or circuit, passes through a ferromagnetic metal at all points. A horseshoe magnet has an air gap between its two poles; the keeper closes this gap. A bar magnet, left by itself, will lose its strength over several months. Though a bar magnet has no “keeper,” if you lay two bars side by side, with the north pole of one touching the south pole of the other, they form a magnetic loop in iron and preserve the strength of both magnets.

                • This reply was modified 4 years, 6 months ago by crosbyman.

                Well, as the old saying goes, “you learn something new every day”. Thanks for posting this crosbyman. After reading your post, I googled magnetic circuit and found everything I ever wanted to know about circuit models, magnetomagnetic force, magnetic flux, reluctance, and a number of other things I vaguely remember studying in science and physics classes a LONG time ago. Also found a “keeper” is also known as an “armature” which sure sounds familiar.

                So if I just put a common steel hex bolt across my Champion flywheel magnets, I should be OK.

                Bob

                1937 Champion D2C Deluxe Lite Twin
                1954 Johnson CD-11
                1955 Johnson QD-16
                1957 Evinrude Fastwin 18
                1957 Evinrude 3022
                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."

                • This reply was modified 4 years, 6 months ago by Bob Wight.
                #237822
                NeptuneMadness
                Participant

                  So a piece of steel would work as a keeper? And should it pretty much fill the whole gap? fit in somewhat snug?

                  #237849
                  crosbyman
                  Participant

                    Canada Member

                    as the saying goes… big is better ..probably the same for magnets

                    Joining AOMCI has priviledges 🙂

                    #237890
                    NeptuneMadness
                    Participant

                      Easy enough! Thank you sir

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