Weak magneto spark

grandpa Love · Feb 19, 2022

Got a cub with a mag. Been driving it couple days a week for a couple months. Today I fired it up and drove it a couple minutes, shut it off to run a kill wire to mag. Tried to start it no go. Unhooked kill wire. No start. Checked for spark, plugs ain't firing, checked coil wire nothing. Strange, was running 5 minutes before. Swapped mags, timing is correct, I have plenty of gas flow. 'new' mag is sparking plugs, but it's a weak orange spark and tractor won't run. Any thoughts?

Janicholson · Feb 19, 2022

The first mag might have the insulator, where the kill switch wire attaches, grounded to the mag frame. It could also be that the connection inside became shorted to ground.
The second mag may have the points out of adjustment they really depend on being set correctly at .013inch.
The magnets can get weak, but not commonly. Jim

Stroby · Feb 20, 2022

I've had a spec of rust/metal get in that little area between the mag and the outside case. I used a business card on one, slid it in there, moved it the full 360 and it fired up. Those things can be aggravating.

KenL · Feb 20, 2022

In the last year. I had one where the magnets were weak and needed to get re-magnetized and the coil was weak in another. They both acted the same way.

grandpa Love · Feb 20, 2022

My wife reminded me that the second mag had been in another cub, we fought it for a couple days. First couple times we tried it , the cub would fire up and run poorly for about 15-20 seconds. After a few attempts it stopped running at all. Tried everything. Swapped it for a distributor, fired right up. Wish she had reminded me before I wasted time with it on this tractor......

Dave BN · Feb 20, 2022

My first thought was that you disturbed the insulator by the condenser when you hooked up the kill wire. As for the second mag, I don't know you just have to check it further.
Dave

grandpa Love · Feb 20, 2022

Dave. Finger tight on the kill wire stud.... Good rubber washer behind the stationary nut on stud. Will open it up this afternoon and see. Mind blown, it was running fine. 5 minutes later nothing. This is on the yellow Lo-boy.

560Dennis · Feb 20, 2022

Had a problem like that with Farmall C magneto !
, I put in new coil ,points and condenser in it as part of the maintenance, been sitting in barn for 25 or more years.
After I did that the next spring the tractor acted like that. No spark
I change the condenser ,been running good ever since . I would like point out I dont know for sure it was a bad condenser , I never tested the condenser ,only with a vom it seemed to work. But I dont have a condenser tester. They are cheap enough just trash it and moved on.
Dont like throwing parts at a problem ,but in this case ,its what happened . And it worked . I cant prove it but new condensers are not made with the highest quality materials or processing over seas ,I feel so I say to be sure test it if possible.
Like the Goodson guy Monaghan says ,if you dont measure ,your just guessing !
Guess I guessed right .
Enough guessing
Good luck

Weak magneto spark

grandpa Love

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Janicholson

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Stroby

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KenL

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grandpa Love

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Dave BN

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grandpa Love

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560Dennis

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