[Farmall] M magneto

[oldiron62 at gmail.com]

I would look for a distributer (sp) on ebay, change the mag out.
They give a lot more probablem`s and are reliable.
I think one off an H will also fit, and some of the # series tractors as 
well. Those old mag`s have a fiber gear that looses teeth, along with other 
things that are hard to come by in a hurry.
Good luck
 K Mosier


----- Original Message ----- 
From: "William Ransom" <wllmrnsm89 at gmail.com>
To: "Farmall/IHC mailing list" <farmall at lists.antique-tractor.com>
Sent: Saturday, July 10, 2010 7:11 PM
Subject: [Farmall] M magneto


>I last had the Farmall M running in 2006. When I tried to start it in 2007 
>and 2008, it seemed to be trying to start, but it wouldn't actually run. 
>Last year, I tried again to start it, and that time the engine didn't seem 
>to fire at all. Today I decided to check the magneto. When I checked it 
>before (by turning the fan by hand with the end of the coil wire close to 
>one of the clips that hold the distributor cap on), I would usually get a 
>spark, which often looked orange or white. Today, I didn't get any spark, 
>so I decided to take the magneto apart. First I measured the resistance of 
>the coil and found it was about 12k ohms (between the terminal on top of 
>the coil and the outside of the magneto). Then, I measured the resistance 
>across the points and found that it was about 1 ohm, whether the points 
>were open or closed. At first I thought maybe the condenser was the 
>problem, so I tried removing the condenser, but that didn't make any 
>difference. Then, I disconnected the coil!
>  from the points, and with the coil disconnected, the resistance across 
> the points still seemed to be about 1 ohm with the points closed, but 
> nothing conducted any electricity across the points when they were open. 
> After I disconnected it, the resistance between the red wire on the side 
> of the coil (the one that's supposed to go to the condenser and points) 
> and the outside of the magneto seemed to be about 1 ohm, so I think there 
> must be a short inside the coil that shorts across the points and 
> condenser. Do you think the coil needs to be replaced? How do you remove 
> the coil?
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