Magneto Help

Discussion in 'Farm Machinery and Construction Equipment' started by hashbrown, Oct 1, 2017.

  1. hashbrown

    hashbrown Peckerwood

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    I got the magneto a part come to find out I went about it the wrong way. This is like is like a distributor so nothing got any heat. The rotor looks great points are good but will not fire.

    [ame]https://www.youtube.com/watch?v=JKeeNYQGOBY[/ame]
     
  2. Tirediron

    Tirediron RockyMountainCanadian

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    it looks like the points might not be closing all the way. with the points close gently measure the resistance with a multi meter on each side without pushing them together, the electrical contact surface rarely wears on mags, because the often switch polarity on start up and balance any material transfer, but the rubbing block still wears so the gap may change.
     
    Last edited: Oct 2, 2017

  3. hashbrown

    hashbrown Peckerwood

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    Ive got it off of the engine I'll check it out tomorrow evening. The last time I fired the old girl up she ran very well.

    [ame]https://www.youtube.com/watch?v=RfpjnDa39XY[/ame]
     
  4. Tirediron

    Tirediron RockyMountainCanadian

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    I have had tractor engine go from running like a top to no start in a 5 minute shutdown. Those old low speeds don't need much spark to run sweet
     
  5. LincTex

    LincTex Jack of all trades?

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    Point gap looks too large.

    Is the magnet still magnetized?

    What engine is that?
     
  6. RedBeard

    RedBeard Guest

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    Not that it matters now but how does expanding a cap that foes over something make it more stuck? The bakelite piece in the pic appears to be a cap not a plug, maybe im missing something. ...
     
  7. RedBeard

    RedBeard Guest

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    Interesting note on the points:
    http://www.splitdorfreg.com/blancard/magproblems.html

    Platinum vs. Tungsten points
    Over the many years a magneto has been on the road, it is likely that some service has been performed on it. The most likely being replacement of the points and oiling the bearings. Most magneto manufactures specified the use of platinum points as opposed to tungsten points commonly used in battery and coil ignition systems. If tungsten points have been installed in your magneto, it may work fine for a while but it will soon lose its ability to provide a hot spark under low RPM.
     
  8. hashbrown

    hashbrown Peckerwood

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    I think the main point you are missing is the spark plug wires are molded into the cap. It would be like heating the distributor on your car with a torch with the cap and wires still in place.
     
  9. LincTex

    LincTex Jack of all trades?

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    Clean the points WELL.
    Close the gap a tiny bit...
    Check magnetivity of the magnets. They lose power over time.

    You might be able to get two BIG neodymium magnets and set them right on top of your horseshoe magnet, on each side. (N to S, S to N).

    If NONE of that works, take the mag apart and re-magnetize your original magnet.

    And if that STILL doesn't work, convert it to MSD! :D;):p
     
  10. Flight1630

    Flight1630 Junior Member

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    Have to zoom in fairly good but Here is (professor) Xavier university. Will this help you with your magneto problem (Think X men)
    Lol

    [​IMG]
     
  11. SheepdogPRS

    SheepdogPRS Newbie

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    Replace the points. Cleaned points don't last or make good connections. Check that the points are grounded and the leads are not. Burnish the new points by closing them on a clean piece of card stock (heavy paper) to remove the protective coating that the manufacturer uses to make them shiny. Be sure to align the point contacts with each other.
     
  12. LincTex

    LincTex Jack of all trades?

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    I doubt they are very easy to find for this old engine.

    I've got points in an old tractor that are 50+ years old. The secret is to keep the point file away from them. A little 600 grit paper once every 5-10 cleans them up, and I use "brown paper bag" paper to clean then a couple times a year. Takes 30 seconds from start to finish.
     
  13. RedBeard

    RedBeard Guest

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    That's not true. Manufacturers recommend you clean them at intervals because they know that they will oxidize from the moisture in the air. In fact cleaning them help your condenser last longer.
     
  14. SheepdogPRS

    SheepdogPRS Newbie

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    As an old electrical tech I will assure you that cleaning them, even with Crocus Cloth, leaves minute ridges and valleys that burn and cause faster wear. Burnishing with a brown paper bag is an excellent way to get rid of oxidation.
    There are resources for wear parts for equipment that is more than 100 years old. Check with a local farm supply NAPA store. Their parts guys are usually good enough to find anything you need.