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Briggs Magneto Replacement

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Got the flywheel exposed, and wires are all shorted to ground.  No wonder it had a coil added.


Got a new magneto but when I mount it with the side that says "this side Out" the spark plug wire is to short.


Does it matter if I install other way, so the plug wire is long enough?


Or was the wrong mag in the box?

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Ronald Hribar

it has to be mounted that way.

The spark plug wire usually seems to be short.

But it does fit.

And if it doesn't, then possibility that it  is wrong coil

Was there any thing left of old coil?

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Pretty sure its a points coil.  Looks like the one I took off.   Is there any way to ID the coil?  NO stamped P/N that I can see.


I have not got back to this, Ron had said the coil wire always seems short but fits.  Going to check that first.


Then maybe source a coil locally, instead ot E-bay.


Anyone used the aftermarket coils from Stens or somewhere else?



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Here's a comparison pic of the coils:


The Magnetron is on the left (notice lump at bottom left of windings); old points coil on right.

(And if you look close at the Magnetron coil, you'll notice the exposed wiring on the right - When the PO installed the wrong ignition switch and +12v is fed to the coil that's what happens)

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Thanks guys.

Bill, your pictures made it clear that the one I got in the box was a magnetron coil.

Ron, went back and looked at the old coil, it is a normal coil no magnetron bump. and is yellow like aftermarkets I have seen pictures of on the web.


Makes me wonder though what the flywheel is polarized for , the standard or magnetron.


On the shroud just below the stamped model number/spec number there is a sticker with what looks like a serial number.

Could this engine have been short blocked?




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A stock flywheel has two red stripes if it is for Magnetron ignition per the parts book:


Your type number (0126 I think) shows the flywheel to be a points and condenser system.

Don't know if the flywheel is repolarized if they add the red stripes.

EDIT: Just noticed the engine is a 325431, not the standard horizontal Briggs that are normally in our tractors.  The above parts list is for the 326400 series.  I would think the red striping would still apply.

Edited by PhanDad
Engine ID noticed

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Bought another coil, of the right part number per my parts list and the dealers

Way short on spark plug wire length.  What is going on?

Pulled another 16hp briggs  apart and measured the spark plug lead. 16.5"

Current Briggs 298968 about 11"

Found an after market coil from Jacks that has a 17-18" lead length.


Ordered that and we will see how that works out.

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Put the Jacks coil on, plug wire was just long enough. 

Put it all back together, wrapped a pull start rope around the booster fan, bright white spark dOd

The guy at the Briggs parts dealer said he was going to ask Briggs what was up with the short wire.


Same engine,  does it matter that the center thru hole on the booster fan is larger than the protruding shaft?


Edited by GregB

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