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Vaccuum Cut Out Switch

bill_w

bill_w

Advanced Contributor
I know that this device is supposed to kill the bottom plug when the throttle is cut in a hurry. My question, is it really necessary? I have a 64 40 hp Gale (OMC), with all of the original wiring cut out of it. I can figure out how to ground the points to kill the engine, but how to wire in the vaccuum switch isn't shown in any of my manuals. Another thing, there are 2 mercury switches on the throttle pinion gear. I'm used to seeing one, so that the starter won't work when the throttle is turned too far up, but what does the 2nd mercury switch do?

If anyone has a wiring diagram for something similar, it would be a great help to me.

thanks in advance,
Bill
 
The cut-out switch is there for a reason !----------On the 2 cylinder 25 thru 40 HP it protecs the motor from a runaway condition in nuetral as well.------It is best not to remove it and they are relatively " trouble free " too.
 
kimcrwbr1 said:
the two black wires coming out of the armature plate (kill wires) normally one goes to the ignition m terminal and the other goes to the center of the cutout switch and the other wire that goes to the other m terminal goes to the center terminal also. The terminal on the mounting bolt is the ground that should go through the micro switch to the start solenoid. Some of those older motors had the second micro switch that youd turn the motor off if the boat turned over just disable or eliminate those two wires and fire that mother up.
Click to expand...

OK, I think I have it. One black lead from points to ignition switch. Other black lead to center post of vaccuum switch, from there to ignition switch, same terminal (M) as first black wire. Ground terminal on vaccuum switch to micro switch under flywheel, then from the micro switch to the ground terminal on solenoid. What about the mercury switches on the tiller gear? In the line to the positive side of the solenoid, I'm guessing, so the motor won't start at high speed? But why 2 mercury switches? One for the negative lead too?

Thanks,
Bill
 
OK...I do have the micro switch. And I never thought about what happens when both point sets are connected..that's why I ask questions. I won't have an ignition switch, just a push button to start the motor, and one to stop it. So the wires from the points don't have to go to ground to stop the motor, just together? That makes finding a stop switch easier. Any toggle switch will work. And I don't have wires to trace, that's my whole problem. Other than the two leads from the points, I have nothing, just cut off ring terminals on the vaccuum switch, micro switch under the flywheel, and the 2 mercury switches on the throttle.

I'm wondering if the PO had ignition troubles, tried to re-wire it, and gave up. There are brand new OMC coils and points under the flywheel. When I was cranking it on the starter, I had no spark. Turns out one plug wire was pinched and grounding out, the other one didn't have a connection at the plug end. New wires, great spark, and a semi-running motor. Needs the carb done, filter changed, some lower unit work, and it should be a great motor.
 
If I rember right, one mercury switch was for the starter solenoid so you couldn't start it at full throttle. The other mercury switch was connected to the side of the block to the vacuum cut out. Those mtrs could run away in neutral when over reved. When you paniced and pulled the throttle back and the vacuum was high in the switch it would complete a circuit to the mercury switch and ground out spark to # 2 cyl slowing the mtr down.
 
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