Something I wasn't able to find about magnetos

[Fisherman6]

after much online searching and manual reading, was that the the armature plate must have good electrical conductivity with the powerhead retainer. I assumed that since it rotated it needed grease and I used an ordinary grease and my spark became erratic. Is there a special conductive lube, or does aluminum slide on brass without any?

Thanks

P.S. Recent owner of a 1970 Evinrude Fisherman 6 hp, I find this forum an excellent resource.

 

[F_R]

Re: Something I wasn't able to find about magnetos

Well, the answer depends. What motor are we talking about? If we are talking about the OMC Universal Magneto, with the coils under the flywheel, it is the SPARK high voltage that has to get through that mount to the armature plate. Since it is high voltage, that is no problem, and no special grounding efforts are necessary.

Now, there are other motors where the armature plate is mounted on plastic bearings of some sort. Those typically will have a ground wire to create a circuit return.

Still others have the spark coils mounted externallly and need a primary circuit ground return.

 

[Fisherman6]

Re: Something I wasn't able to find about magnetos

I'm "talking about the OMC Universal Magneto, with the coils under the flywheel, it is the SPARK high voltage that has to get through that mount to the armature plate. Since it is high voltage, that is no problem, and no special grounding efforts are necessary. "

Well, I had intermittent spark until I removed the grease, so a clean ground helps. You gave me an idea, I'll just run a ground wire from the armature plate to an engine ground, if the plug wires can flex that much then so can the wire I'll run.

Update, consistent spark with wire installed.