1952 Johnson QD-12 Carb

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  • June 26, 2019 at 12:22 am #177980
    mike2923
    Participant

      I recently purchased a 1952 Johnson QD-12 motor and have been going through it trying to get it fixed up. This is my first time using a pressurized fuel tank and it has me questioning a few things.

      I got the motor running, but when I shut it down, gas keeps getting pushed from the tank and ends up getting forced out of the carb. Is this normal with a pressurized tank or is there something going on with the carb?

      Any info is appreciated. Thanks!

      -Mike

      June 26, 2019 at 4:19 am #177981
      frankr
      Participant

        US Member

        How much gas? If it is a significant amount, it is not normal and the float or float valve are not doing their job. However, if we are talking about a bit of gas, like overnight, that borders on “normal” and “fact of life” and is because the float valve can’t be relied on as 100% perfect. For that reason, you should loosen the gas cap when shutting down for the day, Besides, that hiss when you loosen the cap is a very satisfying climax to a good day on the water.

        • This reply was modified 4 years, 10 months ago by frankr.
        June 27, 2019 at 1:33 am #178039
        mike2923
        Participant

          I’d say it’s a significant amount. Probably about 1/4 of the bowl or so spills out of the carb immediately after I shut down the motor. Like you said, I’ve been opening the gas cap to relieve the pressure, but by that time it’s already spilled out everywhere.

          I took the carb apart to clean it when I was going through the motor. The float seemed like it barely moved the needle when I was checking it. What I mean is that it seemed like a lot less throw than I’m used to seeing. I’m not familiar with this style carb. Is the throw an abnormally tiny amount on this style?

          Thanks for the reply!

          June 27, 2019 at 6:04 am #178041
          RICHARD A. WHITE
          Participant

            Lifetime Member

            This would only maybe would only solve one of the problems but release the pressure on the tank before shutting the motor down.

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

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