Correct plug for Elto Cub?

[lagrue]

I’m currently restoring a barn find Elto Cub. Restoration is going well, but I’m having trouble with the spark plug.

I’d like to install a proper threaded plug wire connection plug, but all I’ve been able to find is a slip on/friction type for use with a boot.

From the reference below, I ordered a Champion RJ12C (only plug I can find that cross references from the J12 listed in the link), but as mentioned above, it does not have the correct connection.

http://www.oldengine.org/members/diesel … ppmar2.htm

http://www.sparkplug-crossreference.com … AMP_PN/J12

Its been too long since I spent time close up with spark plugs (I work in the diesel engine industry) to decifer Champion’s code.

Any help would be greatly appreciated!

[eltoquad]

If your Cub had a J12 in it that’s not the correct plug. A J6C would be recommended today. A RJ12C is a resistor plug which your magneto might not even fire under compression (what little of it Cubs have)

[lagrue]

Excellent info! Thank you.

J12 is what is listed in the reference link I put up.

I’ve got some J6C’s on hand for other Evinrudes that I own. Will put them to use!

[The Boat House]

The original plug could have been a
H-10 or a J-4. That chart is from an
Evinrude / Elto Manual. As there is
nothing listed after 1946. That would
indacate when it was printed and these
should be the original plug numbers.
This is the plug I found in this motor
when I got it.You could watch eBay
and in time you may find an original
plug depending how common there
use was at the time.

The lower chart is from the Peter Hunn
book and were probably available at the
time of publication but are no longer.

I believe this is the correct boot.
Nobody has it that I know of.

This guy has the plug wire with the correct end.

http://www.ebay.com/itm/ANTIQUE-OLD-GAS-ENGINE-SPARK-IGNITION-WIRE-BRIGGS-WM-WMB-WI-N-U-I-BLACK-/252696929699?epid=0&hash=item3ad5e925a3:m:mKVX3LonfWez6QddVJZlZBw

[amuller]

It is possible to buy those crimp-on eyelets from an old ignition parts place, but you don’t really need them. A couple of small brass washers and wrapping the wire around them will do. Or, you can wrap the wire into an eyelet and solder. (I think a soldered eyelet is more likely to fatigue and break if it flaps around….)

Likewise, a fair number of plugs do come with a threaded-on push connector, which you can take off and use a knurled nut. (There is more than one thread size, though).

[garry-in-michigan]

The factory received complaints from people stripping out the spark plug holes on the Mate and Cub. In 1940 they increased the length of the spark plug hole and switched to the longer H-10J Champion spark plug. The J-12J will work on the newer models if you’re careful. If you put the H-10J in the older model, the piston will close the spark plug gap. . . 😕

[lagrue]

Thanks much for the information everyone.

I definitely have an early engine (SN is sub 600), so that tells me I need to get that J12 out of there.

[garry-in-michigan]

NO – the J-12 is the correct plug for the older motors . . .

[joecb]

OOPS! that OMC chart shows J4 this can’t be correct as that is a very cold plug compared to a J12 or H10. I would think that the little Cub would foul a cold plug pretty quickly.

Joe B

[RICHARD A. WHITE]

I have 2 NOS H10 plugs, they are still in the package… I do NOT need them, they do not have the tips that unscrew…

http://www.richardsoutboardtools.com
classicomctools@gmail.com

[Author]

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