1960 Evinrude 40 HP, mercury switch

[Evinrude Boater]

What's the mercury switch for on the throttle? There seems to be two of them side by side but only one wire. My motor stand isn't angled back like a transom so my motor is tilted slightly forward when I work on it. Will this make a difference?

 

[F_R]

Re: 1960 Evinrude 40 HP, mercury switch

Dual mercury switches are supposed to have two wires, plus a ground wire. If you don't have all three, the switch is shot.

Mercury switch #1 completes the ground return for the vacuum cut-out switch which prevents motor run-away under no-load conditons. But it only does that function at low throttle positions. That is what the mercury switch does. Otherwise, the vacuum switch can cause mis-firing at cruise throttle settings.

Mercury switch #2 completes the ground return from the starter solenoid pull-in coil. It's purpose is to prevent starting the motor at fast throttle settings and running over something or somebody. Send me a PM if you are interested in a new one. This switch is subject to instant wire burn-off if somebody tries to use a car solenoid.

 

[Evinrude Boater]

Re: 1960 Evinrude 40 HP, mercury switch

What are the pitfalls of disabling these switches, as one already has been?

 

[Evinrude Boater]

Re: 1960 Evinrude 40 HP, mercury switch

It looks as though switch one has been bypassed by a manual ground toggle switch connecting the cut-out switch to ground.
Being a switch activated by its level, I'm wondering if having my motor tilted slightly forward is having an effect on its operation. As the engine jiggles when it cranks it seems to also cut out.

 

[Evinrude Boater]

Re: 1960 Evinrude 40 HP, mercury switch

Somehow I got it to crank and fire and almost run but something in the magneto is scrubbing the flywheel. Doesn't sound good!

 

[spy1309]

Re: 1960 Evinrude 40 HP, mercury switch

Envirude_boater I have the same engine like yours and same year.
I was wondering about those mercury swiches to, I got a hang pretty much how they work, F_R gave you the best description.
There are 2 switches one has 2 wires on it and the other one only one wire and I dont understand how it works with only one given that the other contact ( metal body) is not attached to the ground or anything else.
I have problems stoping the motor from the ignition switch ...do you have any problem?
Also on my vacuum saftey switch I have two black wires connected to the main lead but the manual shows only one wire.
Can you please tell me how many wire you have attached to the vacuum safety switch? or can you send me a picture is pretty rare to find somebody with the same year engine and model, I can help you with some other questions if you need.
I just completed the coils, points and cindenser replacement if you need help let me know.

''It looks as though switch one has been bypassed by a manual ground toggle switch connecting the cut-out switch to ground."

The reason they did that is because the previous owner had the same problem like me he couldn t stop the motor from the ignition switch, as the last resort I will do the same but I suspect that is something wrong with the wireing at the mercury switches or atthe vacuum safety switch.

 

[tashasdaddy]

Re: 1960 Evinrude 40 HP, mercury switch

the base of the coil is probably rubbing the flywheel.

 

[F_R]

Re: 1960 Evinrude 40 HP, mercury switch

Spy, go to aomci.org. Go to Ask-A-Member forum. Scroll down to 8/14/07 thread titled 1960 Evinrude 40hp Wiring Hlep Wanted. Read the thread.

 

[spy1309]

Re: 1960 Evinrude 40 HP, mercury switch

F_R dude hat down you are one of the most helpful dude on this forum

LOL but still I don t get it F_R the electrical circuit was very helpful, I checked againt mine and is the same so pure and simple I see go diference or a misconected wire, now if there is no ground at the ignition switch how do you kill the engine? buy shorting the 2 M terminal ( in the ignition switch)? they are botg positive so I don t think it will work.
And the guy from the post you sent me has the same problem, the previous owner installed a kill switch for the same reason.
I start to take this problem personal so far nobody who had it solved it as far as I know

 

[Evinrude Boater]

Re: 1960 Evinrude 40 HP, mercury switch

I haven't got my engine running yet so I can't provide any help on stopping it. My two mercury switches were not grounded and only the second switch had a wire connected to it. The switches appear to have a metal tangs to fold over on the wires to hold them in place. When I clipped a jumper wire from the tangs to the engine ground, the engine cranked. I noticed that if I twisted the throttle control past "Start", it would not crank.
I think I have a new ignition installed since it has only three terminals, "BAT", "SOL" and "IGN". There was nothing connected to the "IGN" terminal.

 

[F_R]

Re: 1960 Evinrude 40 HP, mercury switch

The two M terminals short together internally in the switch "off" position. That connects the two sets of magneto breaker points together, which kills the spark and stops the motor.

If you don't have two M trminals you don't have the correct switch. You have a battery ignition (car) switch. It will blow up a coil if you connect the IGN terminal to one of the black wires.

 

[spy1309]

Re: 1960 Evinrude 40 HP, mercury switch

Envirude _boater the help goes both ways if you need help with pictures or any info I will help you, my wireing is original so I can help you with that to if you need help.

 

[Evinrude Boater]

Re: 1960 Evinrude 40 HP, mercury switch

Thanks spy1309, I'm wondering why your motor doesn't turn off if your wiring is original. I have to ask, "How do you know it's original wiring and the original gas tank"?
I have to take the flywheel off to check what's rubbing. How did you hold your flywheel to loosen the nut?

 

[spy1309]

Re: 1960 Evinrude 40 HP, mercury switch

I took a channel lock opened it as wide as I got allowed,then I proped the half mouth edge of the plyer on the flywheel tooth and the arms of the plyer were resting against the thermostat housing for leverage, It got out nice and easy.
The tank has the year stamped on it and the Johnson instructions of how to and how much gas you have to mix plus the capacity of the tank in regular gallons and imperial gallons.
The wireing goes to junction box is easy to see that is the original one as insolation on the wire tell you that is discolored and is the original color plus the connections tarnished by the number of year they were in contact with the elements.
Be careful with the flywheel don t mess it up, if you have problems to remove it and you will don t force it.
If you encounter problems I will tell you the steps I did to come out nice and easy.

 

[Evinrude Boater]

Re: 1960 Evinrude 40 HP, mercury switch

Can I e-mail you directly? I have difficulty attaching photos to iboats. Besides I don't want to fill up iboats with our ramblings.
semenuk1@hotmail.com

 

[Evinrude Boater]

Re: 1960 Evinrude 40 HP, mercury switch

the base of the coil is probably rubbing the flywheel.

I got the flywheel off and the rubbing problem was a tooth broken off the manual starter ratchet plate. The flywheel inspection hole cover is missing so a tooth fell in there and was hitting the perimeter of the ignition assembly. Luckily no damage that I can see. The rest of the teeth were found down in the bottom engine cover. Good thing I didn't get it running; it could have catastrophic.