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Magneto Trouble How to Test and What is next?

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buddylindsey
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Joined: Sun Mar 26, 2023 11:35 pm
Zip Code: 74864

Magneto Trouble How to Test and What is next?

Postby buddylindsey » Tue Mar 19, 2024 10:17 pm

First I have no idea what I am doing, I am still learning. Reading manuals, forums, magazines, and YouTube so...

I am not getting any spark from my magneto. I replaced the points and condensor, no luck.

After that I replaced the coil tonight. It is too late to try and put it on the cub tonight so I can't test it.

Is there a way to test if it is working? It seems like if I turn the magneto it should spark, but I get nothing. I just realized I am probably turning it the wrong direction.

I tried putting a cable on the ground where the button connects and touching it to metal, and still nothing.

I am hoping tomorrow or Thursday to be able to put it back on the cub and give it a shot.

However, is there a way I can test before hand?

If I am still not getting spark, is there something else I could check?
Attachments
magneto2.jpg
magneto1.jpg

buddylindsey
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Re: Magneto Trouble How to Test and What is next?

Postby buddylindsey » Tue Mar 19, 2024 10:32 pm

Since I realized I was probably spinning it the wrong direction I went back out and spun it the correct direction, and I got spark. WOOHOO. Now, if I can get some time tomorrow to put it on my cub it will be amazing.

I also had my finger in the wrong place and also felt the shock :D that was fun.

inairam
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Re: Magneto Trouble How to Test and What is next?

Postby inairam » Wed Mar 20, 2024 6:27 am

There is a whole timing procedure for replacing the mag. Make sure you read up on it.

There are also some YouTube videos. https://youtu.be/QqucExhxXdE?si=1aUcyYK9uJPt-T-q
When you only have 9 horsepower you need to know the names of all of the ponies!

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ricky racer
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Re: Magneto Trouble How to Test and What is next?

Postby ricky racer » Wed Mar 20, 2024 8:55 am

buddylindsey wrote:I also had my finger in the wrong place and also felt the shock :D that was fun.


That will wake you right up!! :lol:
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Glen
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Re: Magneto Trouble How to Test and What is next?

Postby Glen » Wed Mar 20, 2024 6:50 pm

Hi,
They have said on here to not turn the magneto and make it spark without somewhere for the spark to go. It can damage the magneto to turn it and make sparks without somewhere for the spark to ground.
Put a spark plug wire in the coil post and hold the wire so the end is 1/4" away from the metal of the magneto, or a bare place on the engine block, if the magneto is on the engine.
The spark should be blue or white, and jump the 1/4" gap. A yellow spark is weak, the engine may not run, or run well with a yellow spark.
It is easier to see the spark if the magneto or tractor isn't in bright light.
There is an impulse coupling, it is called, at the magneto drive. It should be hard to turn by hand, then make a snap sound when it releases.
Below are pages from the 1947 Cub owner's manual telling about the magneto.
https://farmallcub.com/rudi_cub/www.cle ... age-30.jpg

The page below tells about flushing the impulse coupling, on the right side of the page. I would do that when the magneto is off the engine.
https://farmallcub.com/rudi_cub/www.cle ... age-31.jpg

The page below tells how to time the magneto to the engine.
https://farmallcub.com/rudi_cub/www.cle ... age-32.jpg
Last edited by Glen on Wed Mar 20, 2024 7:25 pm, edited 1 time in total.

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Glen
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Re: Magneto Trouble How to Test and What is next?

Postby Glen » Wed Mar 20, 2024 7:20 pm

There should be timing marks on the rotor and it's drive gear. Be sure the marks are aligned.
Also, clean the old grease out of the area, and put new grease on the gears, if they haven't been greased lately.
Below is a pic of the timing marks. :)
Attachments
Cub magneto 4.jpg
Cub magneto 4.jpg (25.13 KiB) Viewed 212 times

buddylindsey
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Re: Magneto Trouble How to Test and What is next?

Postby buddylindsey » Sat Mar 30, 2024 9:47 pm

Alright the magneto is on the cub now.

I double checked the timing marks they were correct. New grease looks good.

I ran through the static timing video and my cub does the exact same thing, so my assumption is that it is timed correctly.

Cub still doesn't start, but I think I am going to ask in a different thread some different questions.

I just thought I tested the cable coming out of the top of the coil against the edge of the cub for spark, and it sparked. I did not however test that spark made it to the spark plug... sigh I guess I should double check that too.

On the bright side I am learning. I am trying to do this without asking my father-in-law for help as he could probably solve it in 5 minutes, but I want the struggle so I can learn. And struggle I am. lol.On to the next battle.

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Re: Magneto Trouble How to Test and What is next?

Postby tst » Sat Mar 30, 2024 10:57 pm

spark should be blue, orange is weak NG

buddylindsey
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Re: Magneto Trouble How to Test and What is next?

Postby buddylindsey » Sun Mar 31, 2024 7:48 pm

I unplugged every cable and replugged in. I think some might not have been seated properly.

The spark plugs are now sparking.

I also got the tractor to run for about a minute. It is a bit rough, but it ran. I think it is slightly out of time.
I need to tweak the magneto.

Also need to rebuild the carb, once those are done it should be usable.


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