1956 Johnson 5.5hp Question

Discussion in 'Outboards' started by fgapplegate, Jul 20, 2014.

  1. fgapplegate
    Joined: Jul 2014
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    Location: New Springfield, Ohio

    fgapplegate New Member

    I bought a 1956 Johnson 5.5hp and it ran but needed help. I rebuilt the carb and replaced the impellar. When I run it, it runs for a few minutes and then stops. When I try to pull the cord, it feels like the motor has froze up. But give it time to cool down and it will start up again. Can someone give me an idea of what the issue might be?
  2. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Welcome to the forum.

    It's freezing up. You let it cool and it looses some grip, until you heat it up again. Tear it apart before you destroy what's left of the internals.

    If you're really familiar with this particular engine, you might have a clue about characteristics and manners, but she's trying to tell you something and you're the only one that can hear her. It's possible it's a really simple thing, like blocked cooling passages or something, but if she's getting tight, you're cooking the internals, which should now be suspect. 60 year old engines need to be treated with some care or they can act like the cantankerous ******** they often do.
  3. Barnian
    Joined: Jul 2011
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    Location: New Plymouth, NZ.

    Barnian Junior Member

    I agree with PAR but will go further and say that there is definately a waterflow problem. In fact I'd be willing to bet that a water tube or cooling passage is totally blocked. Could be insect nest, corrosion, crud or perhaps when you replaced the impeller the water tube didn't line up properly or a rubber ring was dislodged. You've got to strip it right down and inspect everything. Go on you can do it. Good luck.

  4. boatbuilder41
    Joined: Feb 2013
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    Location: panama city florida

    boatbuilder41 Senior Member

    those omc engines didnt have needle roller bearings until 1958. The fuel mix ratio is 25:1 not 50:1 like the modern 2 strokes
  5. fgapplegate
    Joined: Jul 2014
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    Location: New Springfield, Ohio

    fgapplegate New Member

    Thank you PAR and Barnian. Sounds like a plan.

  6. kirkp
    Joined: Apr 2014
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    Location: Council Bluffs, Iowa

    kirkp New Member


    Was there any water coming out of the telltale hole on the back of the driveshaft housing? There should be a good flow and you should be able to put your hand on the motor without getting burned. Definitely sounds like a cooling problem to me. Suggest you go to the AOMCI website. Lots of good folk over there that will be able to help you out.
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