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Horvik

Need help with Magnetron Troubles

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Horvik

Howdy;

Working on a running 3416 H, 326431 iron Briggs that had spark, now none. I changed nothing to make it quit, just replaced the oil pan.

Never looked close at this acquisition till of late, and notice there is no wire coming from the point box, and still it ran.The coil on it after checking is a Magnetron. So, I took it off, cleaned her up real good, gapped it, no spark.

Replaced it with a NEW one, same deal, no spark.

So, is there a way to MAKE SURE you have a flywheel compatible with Magnetron?

And what the heck is your idea of what is the problem?

Thanks

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dentwizz

Second that. Magnetron should work unless told not to. If it was running the flywheel had enough to keep going and it was the right polarity. More commonly the grounding wire that controls the 'kill' function has a crack or chafe near where the small wire goes through the sheet metal shroud. Often times the crack in the wire can be so minor as to only act up when wet or contaminated.

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Horvik

Appreciate the help. I pulled the kill wire completely off the coil before the troubleshooting. I am spinning the flywheel by hand, maybe I need to spin it faster to make it spark. Although I finished an identical engine with the magnetron and it threw spark fine just by spinning the flywheel by hand.

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timflury

I think Mr. Murphy might have killed your spark plug.

What are you checking spark with?? The spark plug that was in the engine?

I would invest in the Briggs spark tester and work from there.

I know the article refers to 250 rpm needed for the coil to work properly, but I've read somewhere else that the magic number is closer to 300 rpm.

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Horvik

Thanks for the help.

I am checking it with a brand new plugs, no fire. Going to hook up a starter to get the revs up and check spark that way. Strange how the other engine was spun by hand and got hot blue spark. Got to get her running one way or the other. Winter is on the way!

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dentwizz

As was mentioned, "Cyl"(as printed on the coil) side should be inside. If you have access to the other engine's flywheel you could compare the magnetic force of the flywheels. Sometimes they dissipate but it is pretty unusual.

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Horvik

Hey;

Is there a way to quantify what the pull of the magnets SHOULD BE on the Briggs 16 HP Cast iron flywheel?

Seems to me to be about 1/2 as strong of physical pull as the last one I rebuilt.

All the best

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TimJr

The engine you spun by hand must have been a points engine. Even then, for a magneto to make a spark, I would think the flywheel magnet would have to spin past the coil faster than you can turn it by hand. A battery ignition would spark when turned by hand, because you are just opening and closing the points. And yes, a Magnetron needs about 300RPM to work. Briggs used to make a polarity indicator tool for checking flywheels, but it is no longer available.

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powerking_one

The kill terminal on the coil grounds out the coil/magneto. There have been previous posts/reports where if one accidentally puts +12v onto the terminal, it will fry the coil in short order (and in the case of a Magnetron) probably instantly. The Magnetron is so simple, that there's really much else to troubleshoot; it either works or doesn't. Try another one is my recommendation.

Tom (PK)

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