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1964 Evinrude 40 HP Big Twin

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  • 1964 Evinrude 40 HP Big Twin

    Well, I am back. I have a 1964 Evinrude 40 HP Big Twin. Runs fine at low speeds, cuts back and sometimes stalls after running at high speed for a very short while. I have replaced the fuel pump, fuel lines, plugs, condensor, and points. I have checked inside the gas tank and all is fine. A metal connection goes into the gas tank. There is a screen on the end of it and it is wide open and looks fine. We have noticed air bubbles in the fuel line. They are there at low speeds as well and don't seem to effect the way it runs at low speeds. Does anyone have any further ideas. I appreciate any help. Thanks, Jim

  • #2
    Re: 1964 Evinrude 40 HP Big Twin

    How do you know there are bubbles in the line? You got some of that plastic hose on it? That stuff is great for causing worry. If you had black hose you wouldn't see it and wouldn't be a'worrying. And you will never get it to go away, so quit looking.

    Anyhow, have you checked the high speed orfice jet in the bottom of the carburetor? It is deep in the hole behind the hex drain plug and takes a special screwdriver to get it out. It must be absolutely CLEAN or it won't run correctly at high speed. Absolutely no gum, coating, dirt or anything allowed in there.

    The tool:


    • #3
      Re: 1964 Evinrude 40 HP Big Twin

      Thanks Frank, I will give your idea a try. Thanks for posting pictures of the screw drivers. Jim 1819suny


      • #4
        Re: 1964 Evinrude 40 HP Big Twin

        have you check spark, when it quits, you did not mention coils, they get hot and sometimes fail.
        TEBOW Country

        Please, NO PM's (Private Messages) regarding boat/engine problems. they will not be answered.
        That is what these forums are for. Post your questions, in the appropriate Forum.


        • #5
          Sign up today
          Re: 1964 Evinrude 40 HP Big Twin

          One of the early signs of coils going bad is they work cold and break down when hot. At high speed it acts quickly like you pulled a spark plug wire off...then when cool everything is fine again.

          Bill P.