12vdc is applied at one side of point?

csisommout

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Nov 17, 2008
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Hello, all experts.

Sorry,I have to bother your guys one more time. I have 1964 Evinrude 28 hp, 2 cylinders and model#28402M.
I have intermittent spark at bottom cylinder/ hit and miss that what local marina's machanic said.
My question is it supposed to have 12vdc at the other side of piont comes from cut off switch, when piont is openned?, the top cylinder's point does not have any voltage. how does it get 12vdc tothe piont or cut off switch?

When the pionts closed or openned, are they supposed to get low readings or grounded? Thank you all.
 

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F_R

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Re: 12vdc is applied at one side of point?

No, it is not supposed to get 12V to either of the breaker points. Offhand, I'd say somebody has installed a car ignition switch. It will actually overheat the coil to the point that it explodes.
 

csisommout

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Re: 12vdc is applied at one side of point?

How can you tell it is car ignition switch? looks original/ old.
Aren't you supposed to get 12v from Terminal M, key switch when you have one click or on position?

Any way, I will take that out and inspect it tomorrow. Any other ideas could that be? shorting wire?

Thank you
 

Chinewalker

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Re: 12vdc is applied at one side of point?

Yes, the switch gets 12V, but it has NOTHING to do with the ignition system. The start part of the switch only deals with the starting system (starter motor and solenoid) and does not interact with the ignition system. The run part of the switch is the part that deals with the ignition system and is merely an ON/OFF. That part of the switch should be an open circuit when on, and closed when off.
 

lindy46

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Re: 12vdc is applied at one side of point?

The "M" terminals should NOT have 12 volts going to them. Their only function is to ground the two sets of points together when the switch is turned to the "off" position (via the two black wires which go under the flywheel).
 

F_R

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Re: 12vdc is applied at one side of point?

If it has M terminals, it should not have voltage on them. BUT the voltage could be coming from the other end of the wire--but only if that end is incorrectly wired.
 

csisommout

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Re: 12vdc is applied at one side of point?

Thank you for all value info and time. Let me make sure I understand this,

Do you mean the time motor started running should not be anyvoltage?
or anyposition of ignition switch? Thank you.

P. S Right now I disconnect that terminal M from cut off swtch. will try to start a motor tomorrow. thank you all.
 

F_R

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Re: 12vdc is applied at one side of point?

There should be NO voltage on either M terminal in any switch position when not running. Period. Don't bother checking it while running, that will only confuse you.

That motor has a magneto ignition, generates its own electricity for the ignition. That is why there is no 12V battery supply to it.

In the OFF position, there should be continuity across the two M terminals.
In any other positon, there should be no continuity acrross them (wires disconnected)
 

samo_ott

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Re: 12vdc is applied at one side of point?

This diagram should be close to what you have.
 

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csisommout

Petty Officer 1st Class
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Nov 17, 2008
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Re: 12vdc is applied at one side of point?

Do you konw a magnito ignition switch part# at Iboats? I always order parts from them, they have a quick shipping service. I like that. Thank you very much, this is very big lesson for me. thanks agian
 
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