’55 Johnson 25 hp head questions

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  • September 18, 2016 at 8:23 pm #44261
    RICHARD A. WHITE
    Participant

      Lifetime Member

      And now what… can you see them, that is the bottom piston, with gouges…

      Ugh

      http://www.richardsoutboardtools.com
      classicomctools@gmail.com

      September 18, 2016 at 10:44 pm #44268
      gjonz
      Participant

        That’s pretty common Richard. I’ve seen it a lot. The cylinder on the bottom often has scuffs in the lower quadrant too. Usually the cylinders can be honed out and stay in spec. But I’d replace the piston/s if its to be a daily runner.

        Greg

        September 18, 2016 at 10:57 pm #44270
        RICHARD A. WHITE
        Participant

          Lifetime Member

          It will be sending out request to the usual suppliers to find new piston and rings…

          Thanks guys

          http://www.richardsoutboardtools.com
          classicomctools@gmail.com

          September 19, 2016 at 2:43 am #44284
          crosbyman
          Participant

            Canada Member

            one member did me a stainless one for a 7.5hp as I recall…… maybe he can cut you one for the RD

            My apology on my memory laps…..

            Joining AOMCI has priviledges 🙂

            September 19, 2016 at 4:54 pm #44318
            1946zephyr
            Participant

              If that is the same exhaust plate as the 35, I may likely have one in my stash.

              September 19, 2016 at 7:00 pm #44323
              RICHARD A. WHITE
              Participant

                Lifetime Member

                So here is a question directly related to this issue.
                The original oil used in the 50’s led to much carbon buildup. But today’s are far superior by all accounts.
                Is it possible that running this engine on the best oil, has resulted in an actual cleaning of the combustion chamber? I run the same oil at the same mix ratio in my 1914 Evinrude, and I gotta tell ya…it rolls over soooooooooo much easier since the change.

                Thoughts???

                http://www.richardsoutboardtools.com
                classicomctools@gmail.com

                September 19, 2016 at 9:00 pm #44329
                chris-p
                Participant

                  Oils like XD100 have cleaning agents in them, almost akin to running Carbon Guard in your fuel/oil mix.

                  Those pics, however, look like washing to me.

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