‘57 18 hp Evinrude, ‘67 Evinrude power head

Home › Forum › Ask A Member › ‘57 18 hp Evinrude, ‘67 Evinrude power head

Viewing 6 posts - 1 through 6 (of 6 total)
  • Author
    Posts
  • February 12, 2021 at 8:26 pm #230358
    Geer Pyron
    Participant

      US Member

      Yozers!
      While testing compression on a 1957 18 Hp Evinrude the starter rope yanked back hard enough to scare me and hurt a little.
      (Post script here, the power head is a 18802, I think, a ‘67 18 hp.)
      I was flashed back to the same thing happening to me with an old tractor motor I was working on. That one hurt. Did a little damage.
      So I stopped, put that bad boy back in the shed!
      The scenario was; motor on a stand and in a barrel. All secure. Compression gauge on lower cylinder. Lower cylinder plug not grounded. I know it should have been. Forgot to.
      Upper plug installed with an in-line spark tester. Just for grins ‘cause I had already tested spark multiple times and knew it was good.
      Pulled it easy a couple times then harder. That’s when it yanked back.
      Sorry I don’t know how else to describe it. It’s like the flywheel or starter suddenly, in mid pull, really really wanted to turn the other way.
      I had tried to start the motor previously with no issues (other than not starting!)
      Any suggestions?
      Thanks,
      Geer
      PS I did just come off a couple successfull builds though!
      One, an FDE-12 that had a gaping (well, 1” x 1/2”) hole in the crank case cover that I filled with JB weld (yea, right?!) and so far it’s held!
      The other, a ‘47 SA 7 Anna half that had been having some fuel issues. Ran that for a solid hour yesterday and ran out of gas as I rounded into the boat ramp canal.

      JMGP

      February 12, 2021 at 8:46 pm #230362
      labrador-guy
      Participant

        US MEMBER PAY BY CHECK

        Are the plug wires crossed?

        dale

        February 12, 2021 at 8:49 pm #230363
        Mumbles
        Participant

          You should do a compression test with BOTH plugs out and the leads grounded. That motor fired on you and could have started even though it would have been on only one cylinder. In line spark testers are just that, in line, and a motor will run with them hooked up. It probably kicked back on you because you weren’t expecting it to.

          February 13, 2021 at 11:43 am #230419
          kerry
          Participant

            US Member

            Dont discount that JB on the crankcase. I know of a mid 70s Ev 70 that had JB where a rod tried escaping. About a 1″ hole. Still running fine after 15+ years. Its all about following the prepping instructions carefully.

            If you have too many, AND not enough, you're a collector.

            February 13, 2021 at 7:51 pm #230469
            Geer Pyron
            Participant

              US Member

              Yozers,
              Got the danged thing to run just now.
              I believe the yank back issue was the spark advance being to advanced. That seems to be the most common answer to my question.
              I hadn’t been paying attention to that when I was turning it over last night.
              And in the future I will follow proper testing procedures.
              Thanks for the input!
              G

              JMGP

              February 18, 2021 at 6:56 pm #231181
              outbdnut2
              Participant

                US Member

                It’s possible for a two-stroke engine to kick back and actually start and run backwards like the old Mercury reversing powerheads. Some Polaris and SkiDoo 2-stroke snowmobiles from the early 2000s on up have a reversing button that does just that – kick-starts them backwards as they shut down.
                Dave

              • Author
                Posts
              Viewing 6 posts - 1 through 6 (of 6 total)
              • You must be logged in to reply to this topic.