OMC Coils (1940’s) Testing

[Buccaneer]

The 1945 Gale made Sea King 5 hp I’m working on,
only had one of the two coils test with an ohm meter
on the secondary windings, and it test consistently at around 7K ohms.
I can’t remember if this is normal for these coils or not?

I had a parts engine handy with a mag and two coils.
I could not get a reading on either secondary on those coils,
but got readings on the primary windings around .3 ohms.

I dug around and found three more of these coils, and could
not get a reading on the secondary on any of them.

These coils have four connections, i.e., the primary and secondary
both have their own ground wires.

Out of frustration, I set up the Stevens tester, and of course,
all six coils tested okay, and fired “in specs” a steady
1.3 to 1.5 amps.

I can’t believe that all those coils have “open” secondaries,
and that the Steven’s tester is able to jump the gaps.
Is this possible, or is there some anomaly when testing
these coils with an ohm meter?

I guess I’ll just put the mag back together with two of the best
looking coils and see if I can get spark!

Thanks.

Prepare to be boarded!

[jeff-register]

I had an old Johnson that had two grounds too. One for each winding.

[Tubs]

As noted in your picture these coil have 2
grounds. Be careful with them. The solder
connections can break free (become loose)
very easily on this coil and there is no
known substitute for them as the OMC style
coil is to large.
Tubs

A "Boat House Repair" is one that done without having tools or the skills to do it properly.

[Buccaneer]

Thanks Tubs, I was wondering about a Universal coil swap,
but didn’t do anything further than just “eye it up”, and was
skeptical, but guess I don’t have to go that route now!
Marine Engine has two in stock, but at $99.99 each,
I would need to be working on a Gale “Crown Jewel”,
not my old dilapidated Sea King!

Tubs wrote:

As noted in your picture these coil have 2
grounds. Be careful with them. The solder
connections can break free (become loose)
very easily on this coil and there is no
known substitute for them as the OMC style
coil is to large.
Tubs

Prepare to be boarded!

[Tubs]

A "Boat House Repair" is one that done without having tools or the skills to do it properly.

[Buccaneer]

Tubs, thanks for saving me a lot of “headache”!
One would think there’d be a small engine coil
of some kind that would work out, but finding
anything that was meant for “points” is a problem
too.

Prepare to be boarded!

[Tubs]

There is a coil with a lot of potential as a
substitute for this coil and possibly others
but I don’t know what its for. It is actually a
bit smaller. The center hole is larger but I
believe we could overcome that. It has some
markings but they haven’t been of any help
so far.
Tubs

A "Boat House Repair" is one that done without having tools or the skills to do it properly.

[bobw]

It says Made in USA but I don’t know what that coil goes to either.

Bob

1937 Champion D2C Deluxe Lite Twin
1954 Johnson CD-11
1955 Johnson QD-16
1957 Evinrude Fastwin 18
1958 Johnson QD-19
1958 Johnson FD-12
1959 Johnson QD-20

“Every 20 minute job is only a broken bolt away from a 3-day project.”
"Every time you remove a broken or seized bolt an angel gets his wings."

[Buccaneer]

I was thinking that there must be a coil from a chain saw
from the 60’s or early 70’s, (that still used points) that
might work, but after researching for a while last night,
I haven’t found it yet.

The is a Tecumseh small engine coil, but the plug wire shoots
out of one end instead of the side, and no measurements are
given on the center hole size.

Prepare to be boarded!

[Buccaneer]

I ended up ordering a couple of those cheap, aftermarket coils for
Tecumseh engines. They’re a little loose on the laminations,
and with the way they’re made with the secondary tower
shooting out the end of the coil, they end up 3/16″ taller than
the original coils.
I would have to tear the Sea King back apart to see if the flywheel
would clear.

I mocked up one of the Tecumseh coils on a Gale mag plate that
was loose.
The plug wire would rub on the rotating magnet, unless it’s “bound back”
like in the photo, with a tie wrap.
When I get in the mood, I’ll probably investigate some more,
with the possibility of these working for a coil swap.

The best part about these coils is that they only cost me $29.27
for “two”, with free shipping, off of EBay.

(Ignition Coil For Tecumseh 30546 30560A 30547A 30548B 29632 610768 Lawn Mower)

Prepare to be boarded!

[Author]

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