Eismann coils

[Buccaneer]

I tore the magneto apart on the 1946 twin cylinder Mercury KD4
to clean and “freshen up”. For kicks I checked the coils out with
the ohm meter. First one tested okay, but the second coil seems
to have an open secondary. Retested several times, but always
with the same result. Strange thing is that this motor seem to run
good in the test barrel last Fall.
I’ll throw the coil on the Stevens when I get a chance for a second opinion!

The laminations are 5/8″, so not a direct swap for an OMC universal coil.
Do the laminations on these Merc turn out okay if you grind them down
for an OMC coil?

I’m still having flashbacks of the attempted coil swap on a twin opposed Neptune
with the single Eismann coil. Never did get the B&S coil or the John Deere pony
motor coil to work out on that one!
Thanks.

Prepare to be boarded!

[The Boat House]

• This reply was modified 4 years, 3 months ago by The Boat House.

[billw]

I don’t have a LOT of engines with Eismanns but I have not seen a bad Eismann coil, yet. Just the opposite of Bendix. You’re going to want some new condensers though. If you have a Stevens, do a leakage test on the condensers. My bet is they will not pass that test, even if the engine was running okay.

Long live American manufacturing!

[Buccaneer]

Will check the coil on the Stevens and go from there.
I haven’t bothered to check a condenser on the Stevens
since I first got it. I just always replace or retrofit with
capacitors, and from what I remember, the Stevens
seemed like it was needing a “tune-up” when it came
to testing condensers.

Prepare to be boarded!

[lyks2tinkr]

In my experience all the Eisman coils I’ve seen are bad with the exception of 1 on a Neptune 6hp opposed twin. That coil measures good and throws a nice hot spark.
The secondary windings must have been wound with extra fine wire that just didn’t hold up.

On the coil you have that measures bad but still runs the motor.
The secondary winding is probably broken but the spark is jumping the break. Sooner or later that gap gets too wide and the coil will permanently die.

[Buccaneer]

I checked the coil on the Stevens today. It fired nice at about 1.7 amps.
I’d have to look at what the specs are for that coil.
Then I went to the coil that check good on the Ohm meter,
and couldn’t get it to fire on the Stevens. Not sure what was going
on, but after about 4 tries, monkeying around, it fired at about the same
amps as the other coil.
Time will tell if Tinker is correct about the open winding!

Prepare to be boarded!

[The Boat House]

• This reply was modified 3 years, 2 months ago by The Boat House.

[slim60]

After reading Buccaneer’s post on the attempted Neptune opposed twin coil swap I thought of my 1941 11B4 that’s been hanging in the shed for five years. Would it be possible to run it with a buzz coil?

[The Boat House]

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• This reply was modified 4 years, 3 months ago by The Boat House.
• This reply was modified 4 years, 3 months ago by The Boat House.
• This reply was modified 3 years, 2 months ago by The Boat House.

[The Boat House]

• This reply was modified 4 years, 3 months ago by The Boat House.

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