1956 is 7.5 Johnson Mag

Home › Forum › Ask A Member › 1956 is 7.5 Johnson Mag

Viewing 8 posts - 1 through 8 (of 8 total)
  • Author
    Posts
  • August 16, 2016 at 5:33 pm #4995
    1-old-outboard
    Participant

      Working on a mid 50 7.5 hp. johnson, and was wondering if there should be much play in the mag plate when it is all tightened down. I was thinking the was a washer spring under the mag plate to remove some of the play in the system. Maybe I am thinking of something else. Seems I have some vertical play (rocking) when everything is tightened down. Didn’t think it was normal. Thanks,
      Randy

      August 16, 2016 at 6:20 pm #42189
      chinewalker
      Participant

        US Member

        Randy – is the ring under the retainer flat side up? I’ve come across a few over the years where the plate has been flipped so the tapered side is up, resulting in a sloppy magneto. It wasn’t until much later that they added the wavy washer between the ring and the retainer plate.
        – Scott

        August 16, 2016 at 6:44 pm #42191
        frankr
        Participant

          Actually, the wave washer is used on models with a sliding speed control lever. Models with twist grip throttle don’t have one (too much friction)

          August 16, 2016 at 9:13 pm #42196
          chris-p
          Participant

            Randy,

            if the ring is in fact in the correct orientation(flat up), ensure the brass ring on the ID of the mag plate is not cracked or broken. If the mag plate is fine, and the ring is correct, the slop can be tightened up by making 4 indentations with a flat screwdriver and hammer at the 3, 6, 9 and 12 o clock positions on the mag plate support ring (brass) Don’t hit it too hard, or will be too tight.

            August 19, 2016 at 2:02 am #42328
            1-old-outboard
            Participant

              Sorry been called out on the road, just got internet. Anyways, under ring is with taper up. I will change it this weekend. Sounds like it will cure it. Thanks for the help.
              R

              August 25, 2016 at 11:46 am #42634
              1-old-outboard
              Participant

                Got back to it, and flipped the ring flat side up and all is well. As always Thanks,
                R

                August 25, 2016 at 6:45 pm #42671
                aquasonic
                Participant
                  quote Chris_P:

                  Randy,

                  if the ring is in fact in the correct orientation(flat up), ensure the brass ring on the ID of the mag plate is not cracked or broken. If the mag plate is fine, and the ring is correct, the slop can be tightened up by making 4 indentations with a flat screwdriver and hammer at the 3, 6, 9 and 12 o clock positions on the mag plate support ring (brass) Don’t hit it too hard, or will be too tight.

                  Are the four indentations made by hitting the bottom side of the brass mounting ring creating four small ‘speed bumps’ where the armature plate contacts the brass mounting ring? I recall seeing these on at least one of my motors.

                  I have been told that wear and tear can sometimes cause a loose armature plate, even with the mounting screws tightened down. The loose plate resulting in variable ignition timing and a motor that runs poorly.

                  Improvise-Adapt-Overcome

                  August 25, 2016 at 11:33 pm #42680
                  chris-p
                  Participant

                    Like so. I have tightened up many like this. Don’t need to hit it very hard at all, in fact too hard, and will be too stiff.

                  • Author
                    Posts
                  Viewing 8 posts - 1 through 8 (of 8 total)
                  • You must be logged in to reply to this topic.