Bench test floor test Magneto?

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K_Wiz
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Bench test floor test Magneto?

Postby K_Wiz » Mon May 30, 2022 3:18 pm

In a dark room would this be a good way to check that the magneto is producing spark? Would a good spark be blue, orange or white? My points are set at 0.013. Just making sure so I don’t mess up a coil.
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Stanton
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Re: Bench test floor test Magneto?

Postby Stanton » Mon May 30, 2022 4:07 pm

Believe it should be a strong blue to white spark. By strong, I mean the spark should “jump” a 3/16” - 1/4” gap.

Do a search on here using “blue spark” or “white spark”. Pay particular attention to Rick Spivey’s posts. Always have a ground for the spark to go. Don’t snap the coupling without someplace for the spark to go.
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Jim Becker
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Re: Bench test floor test Magneto?

Postby Jim Becker » Mon May 30, 2022 5:08 pm

No. This is not a good way to test it. If the impulse coupling is working properly, it will stop the magneto rotor (including that nut on the end of it) from rotating until the impulse winds up and releases. Trying to turn the nut directly will just be pushing against the stop of the impulse coupling. The right way to turn it is to rotate the outer part of the coupling (the 2 drive lugs). Wind it up a half turn until it releases. When that happens, it should throw a spark a quarter inch or so. It should be blue and bright enough to see in fairly normal light conditions. If you want to test using that spark plug, open the gap up.

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Re: Bench test floor test Magneto?

Postby Glen » Mon May 30, 2022 6:15 pm

Hi,
My opinion is that you shouldn't have anything connected to the small post on the side of the magneto, for the test, it is for shutting off the engine.
The 1 post ignition switch has 1 wire that goes to the magneto post, it grounds the magneto to stop the engine.

I can't see where the wire from the coil post on the magneto is going in the pic.
It should go to the top of the spark plug.

You should connect a wire with clips to the bottom area of the spark plug, where the place for the wrench is, and the other end of the wire to the case of the magneto, by the mounting area.
That grounds the spark to the magneto.

The spark should be blue or white. Yellow is weak and needs improving, the engine may not run with a yellow spark, they have said on here. :)

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Re: Bench test floor test Magneto?

Postby Jim Becker » Mon May 30, 2022 7:54 pm

Glen wrote:Hi,
My opinion is that you shouldn't have anything connected to the small post on the side of the magneto,

I didn't notice that. I thought that clamp was on the housing of the magneto.

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Re: Bench test floor test Magneto?

Postby K_Wiz » Sun Jun 05, 2022 6:25 am

Thank you! I finally got to the grainery where my cub is parked. I put the magneto back on. Cap wires and plugs touching a ground. Yes, I got a good white blue spark. Thanks again!

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Re: Bench test floor test Magneto?

Postby John *.?-!.* cub owner » Thu Jun 09, 2022 10:36 pm

That is not a good idea. You need to turn the magneto using the ears on the advance, not the nut in the center. Using the ears it winds the spring, then the shell holding the spring pushes the dogs off the stop pin at the right point for the spring to spin the magneto shaft and produce a spark. Turning the nut forces the dogs past the stop pin by brute force until you get to a high enough speed for them to retract. You can do serious damage this way. In addition I would strongly suggest a drill, not an impact wrench.
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