1966 Evinrude Lightwin 3 hp oil mix

Home › Forum › Ask A Member › 1966 Evinrude Lightwin 3 hp oil mix

Viewing 8 posts - 1 through 8 (of 8 total)
  • Author
    Posts
  • June 24, 2015 at 5:22 pm #1852
    mercuryman
    Participant

      I recently purchased a 1966 Model 3602E Lightwin that had thrown a rod through the block. I replaced with a like year power head. The instructions on the front of engine call for 50/1 oil mix. Due you think 50/1 may have caused the rod to burn up. This motor seems to be built the same as older 3 hp engines that use 24/1 mix.

      June 24, 2015 at 6:45 pm #18838
      thepetrolist
      Participant

        According to this manual, pre-1963 models requires 24:1 mix and post 1964 models require 50:1 mix. Scroll to the last page.
        http://www.joeoutboard.com/resources/Ma … f-1964.pdf

        My guess is that some (the) previous owner probably mixed too lean a mixture, if the mixture is at blame. Might have miscalculated and mixed something like 70:1 or 100:1..?

        June 24, 2015 at 8:00 pm #18839
        frankr
        Participant

          US Member

          Whatever caused the failure, you can bet it will be blamed on the oil.

          June 24, 2015 at 8:19 pm #18840
          chinewalker
          Participant

            US Member

            Personally, I would run it richer than 50:1 as it is a plain bearing motor throughout.

            June 25, 2015 at 12:58 am #18860
            david-bartlett
            Participant

              I had a 1968 Lightwin that the manufacturer specified 50:1. I found that it ran a bit on the hot side with that fuel mix, so I went to 24:1 and was much happier. I think the motor was too.

              June 25, 2015 at 3:46 am #18875
              Mumbles
              Participant

                In ’64 OMC changed the oiling requirements for all of their motors from 16:1 or 24:1 to 50:1 without changing the mechanicals inside them.

                Is it just me or does there seem to be more good running classics from the fifties and early sixties than there are from ’64 on? It seems the motors which are fed 16:1 and 24:1 fuel/oil mix don’t want to wear out as quickly as the 50:1 models.

                June 25, 2015 at 7:24 am #18885
                frankr
                Participant

                  US Member

                  I seem to remember that the 1964 change to 50:1 was ONLY if Johnson (or Evinrude) oil was used. Otherwise, the old spec was still in place. So now the question becomes what was different about the oil? The formula was a well guarded secret, but I did hear from a factory engineer that it contained some synthetic oil. One thing I am very confident of is that it was indeed something special. I’d seen that proved over and over again in engines that had been run hot.

                  So..is today’s TC-W3 oil the same as the old J/E TCW oil? I seriously doubt it. I suspect that old TCW oil had some automotive detergents in it. Technology has come a long way since then, and motors do not carbon up anywhere near as badly as they used to. No doubt getting rid of the lead also has something to do with that.

                  June 25, 2015 at 10:13 am #18887
                  1946zephyr
                  Participant

                    16:1 and no less.

                    Mumbles makes a good point, in his second paragraph. The smaller motors got nuked out because of the lighter oil mix. The Lightwin is a 100% friction motor. No needles anywhere. Oil is the cheapest thing you will ever put in an outboard. Don’t skimp on it. 😉

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