Yamaha 25A (648) 1972-1979 Wiring

[martin de Ridder]

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 ?

 

[Mr Efficiency]

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.