Old Johnson Seahorse 5.5

Discussion in 'Outboards' started by Airborneholt, Feb 5, 2017.

  1. Airborneholt
    Joined: Feb 2017
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    Airborneholt Junior Member

    I picked up an old Johnson Seahorse 5 1/2 hp outboard for dirt cheap.
    I rebuil the carb and got it running at full throttle, but every time that turn the handle to a lower throttle setting, it will die. I originally thought that it was fuel relate, but when I holt he throttle linkage on the carb at full throttle and turn the handle down, it still dies.
    Does anybody have any ideas for this? Is something grounding out as I turn the handle?
    Thanks
     
  2. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Welcome to the forum.

    Yep, it's probably the kill switch shorting out in the tiller handle, likely the throttle cable has frayed it's sheathing and chaffed through the wire insulation, making a short when the cable torques up. Disassemble the handle and it'll probably be quite obvious.

    A quick check would be to disconnect the throttle cable at the carb and start it up. Use the carb throttle shaft arm to crank open the throttle. It's likely it'll run fine, with appropriate throttle response, assuming you did a good job on the carb rebuild.
     
  3. Airborneholt
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    Airborneholt Junior Member

    Thanks!
    I'm glad I found this site before I started tearing the fly wheel off.
    I'm out of town for a few days, but I'll give you an update when I get to it.
     
  4. Airborneholt
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    Airborneholt Junior Member


    I opened up the handle and didn't find anything- there isn't anything electrical in the handle. This is a CD-16 model that was manufactured in 1959.

    I ended up pulling the flywheel, but still couldn't find anything that looked like it was grounding out. I also pulled the spark plugs and looked for spark- I am getting spark on both plugs regardless of what position the handle is in.
     
  5. powerabout
    Joined: Nov 2007
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    powerabout Senior Member

    is there a short when the throttle rotates the armature plate as both coil wires and kill wires are moving?
     
  6. Airborneholt
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    Airborneholt Junior Member

    I wonder about that- can I pull the points and everything out from under the flywheel to look at everything?
     
  7. powerabout
    Joined: Nov 2007
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    powerabout Senior Member

    Yes the armature plate that you are looking at from the top when you take the flywheel off is screwed down top of a metal plate that has a retainer ring over it to hold it down.
    All very obvious once you have it apart.
    All those small omc's are similar to 40hp
    Be aware that there are short and long screws holding it down, I think one in each coil go right through and 2 short down low on the armature.
    Get a light from underneath and you will see a couple of threads poking out.
    The coils are on slotted holes because there is a tool to put over them to adjust them out close to the flywheel diameter, so dont undo both coil screws at the same time.
    Also check how much radial slop in the armature plate, its located on a bush on the crankcase, ( you will see all that) if its sloppy it makes hard starting and bad idle.
    They are the best small engines ever made and they will be around for years to come.
     
  8. oletrout
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    oletrout New Member

  9. oletrout
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    oletrout New Member

    What are you calling the handle... is this a twist grip
     
  10. Airborneholt
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    Airborneholt Junior Member

    I still didn't have any luck finding a short, but the coils are rotten and cracked. I will order new ones and replace them (Sierra part 18-5181). At the same time, I might as well change the plug wires. What do you recommend for new wires?
     
  11. Airborneholt
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    Airborneholt Junior Member

    Awesome looking motor! Thanks for sharing. I have the opportunity to pick up a JH19A 3HP for $40 (he claims that its running great)... I'm on the fence about it because I'm running out of places to hide boat motors from my wife.
     
  12. oletrout
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    oletrout New Member

    plug wires

    I had bought a 25 foot roll through Napa autoparts... copper core is what is needed Part number 18-5226 ... also new plug boots and ends
     

  13. oletrout
    Joined: Feb 2017
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    Location: nova scotia

    oletrout New Member

    Boat motors !!! had to make a path through my basement to get at most of mine...
    including 5 British Seagulls... 6- 2 HP Johnson and Evinrudes... 3 1960 3 hp Gales ( omc)..
    couple of mid 70`s 4 hp Johnsons...and 2 4 hp Martins ( https://tinyurl.com/gnf8jt9 )
    4 or 5 mid `60s 3hp Johnsons...probably forgot a few...
     
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