1978 25hp Evinrude - electrical issue

[tmeo]

I just bought an 1978 25hp Evinrude outboard. It's electric start etc, and I need some help with the wiring. <br />There are two very thick wires, one black and one red. I assume these are for the battery.<br />The other ones (4 of them) operate the electric choke, the start, and the kill?<br />Anyway, I would be greatful if someone who knows which is which could tell me. Here is a diagram I have done of the four wires, and thier colors:<br />

<br />Thanks

 

[Hooty]

Re: 1978 25hp Evinrude - electrical issue

Ok Tim,<br />The red wire is 12vdc unfused.<br />Black is ground.<br />Black with yellow stripe is the kill wire (shorts magneto to ground).<br />Yellow with red stripe is the ignition switch to the starter solenoid.<br /><br />c/6<br />Hooty

 

[tmeo]

Re: 1978 25hp Evinrude - electrical issue

Right.....<br />I understand that the big thick black and red wires go to the battery. However, the red wire in the diagram is seperate to the thick ones. (I have 6 wires in all).<br />Now I know what some of the wires do, I just need to know what to attach them to. <br />Do I simply wire it up so that the thin red wire (in the diagram) goes to all the other coloured wires, with a switch in the middle?

 

[ezeke]

Re: 1978 25hp Evinrude - electrical issue

Hi Tim,<br /><br />You need a marine ignition switch if you don't have an external contol with a switch. Is this a tiller motor?<br /><br />The purple and white wire should go to your choke.

 

[tmeo]

Re: 1978 25hp Evinrude - electrical issue

This is on remotes. I am currently fitting out the inside of the boat, so will be putting some switches in. I am very confused with regards to this wiring. <br />With the starter, for example, do I simply connect the thin red wire to one terminal, and the yellow with red stripe to the other?

 

[ezeke]

Re: 1978 25hp Evinrude - electrical issue

The motor runs on its own once started. Basically, the only function of the battery is to turn the starter motor, and to activate the choke. The motor is stopped by grounding with the black and yellow wire when the key is turned to the off position. Because the ground is always active when the key is off, you cannot start the motor manually without turning the key to the run, or middle position.<br /> <br />In other words, you can manually start the motor with the wires disconnected, but there is no easy way to stop it except to disconnect the fuel line.<br /><br />The starter motor is wired to the battery through a solenoid which (the solenoid)is activated when the ignition is in start position. When you release the ignition key the starter stops because its solenoid is no longer active. <br /><br />The more modern switches have a push-in action which activates the choke solenoid. The 1978 control had a separate toggle switch for the choke.<br /><br />As you know, the motor is negative gound, so the positive line feeds power to the the two solenoids, which are already grounded, through the ignition switch. <br /><br />The most important thing when wiring is to have all of your contacts in place and properly connected when the motor is running. Reversing the battery cables, disconnecting the cables, or shorting the cables, while running, can ruin the charging system and even damage the ignition components. These are expensive components. <br /><br />It is well worth the the money to get a service manual specific to your motor model and year. A Bombardier Dealer can get that for you or you can get back to this site and someone may suggest an online source. The OMC Service manuals have a full colour wiring diagram which is really nice to have. <br /><br />Hope this helps.