Early Johnson Coil fitment

[Buccaneer]

I put the magneto back together on the 1936 Johnson A-80,
new capacitors, everything all soldered up, and tested
okay on the Stevens.

Put the flywheel on and the magnet is hitting on one coil
shoe. Tried moving the coil "in" to no avail.
Really not designed for adjustment.

I then noticed that the two coils were switched from
their original location. I actually marked them
before I took the magneto apart, but somehow put
it together without paying attention to that detail. 🙁

Were the coils on these early Johnson’s "custom"
fitted at the factory?

I rather dislike the thought of "un-soldering" things
(especially the new plug wire) but that may be
a better option then trying to ream out the coil
mount holes larger or grinding on the coil shoe
while in place.

I will be totally frustrated if I switch coils and the
flywheel magnets still "hit".

Just wondering if any of you have had a similar experience
and what you did as a remedy?
Thanks.

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Prepare to be boarded!

[Mumbles]

The real early Johnsons had the mag plate turned to fit the flywheel and both items had corresponding numbers stamped on them to identify them as a matched set. One of the service manuals even gives the dimensions for building an arbor to be used for turning different model mag plates but I find a large flat file works just as good.

I start by marking the lams with a Sharpie or something which will show up and then rotating the flywheel to see where the high spots are. After filing it down some, mark the coil again and check the fit. I usually stop once everything is clear but I believe some guys use masking tape on the outside of the lams to set the gap a bit more accurately.

Here’s a poor fitting aftermarket coil being filed down to fit. Same idea.

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[dmbono]

I wouldn’t worry about unsoldering the coils

[Buccaneer]

Thanks for the replies. I determined that only
a shoe on one side of one coil was hitting.
I’ve been using a Dremmel with a little sanding
drum, and a flat file to bring it down. Just about
done. Will have to member to pay more attention
next time to get the coils back in their original
position. Of course if I have to replace a coil
next time, then I could be back in the same boat!

Prepare to be boarded!

[Buccaneer]

Mumbles, I used your idea with a "sharpie".
Worked good for fine tuning the fit.
Flywheel on and have good spark.
Little worried about the flywheel nut,
seems like it’s taking too long to tighten
up. Need to find my flat fan belt / strap wrench
so I can hold the flywheel still !

Prepare to be boarded!

[Author]

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