Yamaha 25A (648) 1972-1979 Wiring

Discussion in 'Outboards' started by martin de Ridder, Jun 8, 2021.

  1. martin de Ridder
    Joined: Jun 2021
    Posts: 1
    Likes: 0, Points: 1
    Location: Netherlands

    martin de Ridder New Member

    Hello fellow sailors,
    First of all English is not my native language so up front I am sorry for my grammar and spelling.
    Now my problem/issue (problems can be solved), I bought a small boat with a cabin and an outboard engine from Yamaha, the 25A.
    It took me a while to get the boat ready for her first voyage and the engine was saved for last, thinking it wouldn't be such a hassle to fix things.

    How wrong I was! lmao. I have a wire that contains 7 colored wires inside that go to a special plug; I also have the counter plug with again 7 wires with the same color codes.

    So far it went well, I hooked up the ignition switch, the emergency stop and the choke switch that took all the wires in the cable so that should be ok; however there are 3 wires coming back out of the bundle and they go no where.

    I did my best to find a wiring diagram for this particular engine but with no success it is just too old I guess. So my best chance is this and other forums and hope someone out there has this diagram laying around.

    The type indicator gives very little information....
    Model 648 / 25A / L / serial number,.... no more no less
    Who can help me get my first voyage this year ?
  2. Mr Efficiency
    Joined: Oct 2010
    Posts: 10,386
    Likes: 1,045, Points: 113, Legacy Rep: 702
    Location: Australia

    Mr Efficiency Senior Member

    I assume the engine isn't running ? If there is a workshop manual still around for the engine, it will contain the wiring diagram, the Mariner 25 hp engine in that era was a re-branded Yamaha I think, so it might help if you can find a manual for that.
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