Ignition wiring - '61 40hp Evinrude LarkIII

Hello - First time on the forum. I have a '61 Evinrude 40hp Lark III. I am trying to sort out the ignition wiring. The starter will engage fine when jumped from the battery. Nothing happens when using the ignition. I am looking for an ignition diagram for this. Wiring appears solid and complete, but not sure if previous owner has it wired correctly. Any help apperciated. I plan to buy a service book soon, but want to work on it right away. Help appreciated.

Re: Ignition wiring - '61 40hp Evinrude LarkIII

Welcome to Iboats, erik!<br />I'm afraid I can't post a wiring diagram since it's copyright, but for the starter circuit it's pretty simple to describe.<br />First, the battery has absolutley nothing to do with the ignition system. It is completly independant. In fact, you can start the engine with no battery whatsover by wrapping a rope around the flywheel and pulling.<br /><br />Ok, here goes:<br />Ground(-) on batt -> Engine block<br />Positive(+) on batt -> One large pole on solenoid.<br />Other Large Pole on solenoid -> post on starter motor.<br /><br />Positive(+) on batt (Brown? little wire) -> keyswitch (batt terminal) <br />Keyswitch (S terminal), white wire -> one little post on solenoid.<br />Other little post on solenoid (white) -> base of the vaccum cutout switch.<br /><br />(The vaccum cutout switch is on the right side of the engine, and has wires and one hose connected to it. It is designed to kill spark if manifold vaccum gets too high, such as in a run-away condition or being revved without load. It can be identified by following to the end the hose that attaches to the intake manifold, just below and to the left of the carburator. The wires on the tip of the vaccum cutout switch are attached to the ignition system)<br /><br />Base of vaccum cutout switch -> saftey switch (white wire)<br /><br />(The saftey switch is on the left hand side of the engine, and is designed to keep the engine from cranking if the throttle is too far advanced)<br /><br />saftey switch -> ground.<br /><br />That's it. I hope this helps!

Re: Ignition wiring - '61 40hp Evinrude LarkIII

Thanks! Are you saying that either of the two small posts on the solenoid can take the S wire from the ignition? It doesn't matter? Does it also not matter which large post on the solenoid the positive battery lead goes to? If I am clear on these points, I should be able to figure it out. Please clarify, and thanks very much. ERIK

Re: Ignition wiring - '61 40hp Evinrude LarkIII

As long as that's the proper marine solenoid, then it doesn't matter which of the large posts or which of the small posts you use. If it's got "ignition coil" "batt" or some such automotive lingo on it, then get back to us. <br />In electronics terms, it's simply a relay. The two small posts are the coil, and the two large posts are a SPST switch.<br /><br />Oh, here's a simplified schematic of what it should look like (ignore the jumper):<br /> <br /><br />(Courtesy of schematic, a member of this board)

Re: Ignition wiring - '61 40hp Evinrude LarkIII

The solenoid has marks S and I at each of the small posts. The ignition also has two black leads that meet a harness plug from the motor. There are two white leads from the motor in the harness, as well; one goes to the second small solenoid post, and the other to the ignition. Your diagram is very simple, but as described, mine has these two extra white wires. Their purpose? Thanks. ERIK

Re: Ignition wiring - '61 40hp Evinrude LarkIII

The two black leads are connected to the magneto coils up under the flywheel. When they're connected together, it kill spark. Watch yourself around them when the engine is running; they've got about a 90v pulse on them that'll get your heart going. They connect to the two 'M' positions on the ignition switch. In the 'run' position, those wires do not connect to anything.<br />I don't know anything about a second white wire going from the engine to the dash. There should be one white wire coming from each pole of the solenoid as I indicated above; one of which runs to the dash, like the yellow traced wire on the schematic above. <br />You may have a tan wire which is used to light the overheat light, but that goes to a light not an ignition switch. Also there may be a grey wire for the tachometer. I take it it's neither of these?<br /><br />Something is connected to the other small post, right? That 'S' and 'I' has me worried, that sounds like an auto solenoid to me. If you can, disconnect both the small terminals and jump from the battery to the two small terminals. If you get a click, then you're ok. If you hear nothing, that's an auto solenoid. In which case, you'll have to use the 'S' terminal and the solenoid mounting bracket until you can get a proper marine solenoid (not pricey).

Re: Ignition wiring - '61 40hp Evinrude LarkIII

yes, the second small post has a white lead which follows to the motor, and as you described the first small post has the white ignition wire. Ignition only has on white lead. If all wiring checks out, but the key won't turn the motor over, then I would have a bad switch or solenoid, correct? Solenoid appears to be brand new.

Re: Ignition wiring - '61 40hp Evinrude LarkIII

Check out the last paragraph I just added above, I'm 90% certain that's an automotive solenoid. Remove the wire from the I terminal and try it on the mounting bracket. Preferably the wire that goes back to the engine.<br /><br />If it's an automotive one, you must replace this solenoid with a marine one. They are sparkproof, keeping your boat fire and gasoline explosion free. Remember, gas vapours sink in air. A car's engine bay has an open bottom. I hope your boat doesn't. <br /> Here's a typical marine outboard one.<br /><br />Outboard Marine type solenoid (posts on top of schematic are the small ones):<br /> <br /><br />Automotive type solenoid (posts on top of the schematic are the large ones):<br />

Re: Ignition wiring - '61 40hp Evinrude LarkIII

Thanks so much for the help! I will be working on it this weekend and will post my results. ERIK