Evinrude Zephyr Plugs and Terminal Ends

[Buccaneer]

Just wondering what others have done with great success and happiness
when replacing plug wires and spark plugs on their good running Zephyrs
(that run with the front cover on)

It originally had “ring” style plug wire terminal ends that are crimped over
the wire strands. Doesn’t appear that re-using the old ones are a good option.
I see these on Brillman. Anybody use them? Are there others or better ones “out there”?

https://brillman.com/product/brass-ring-crimp-spark-plug-magneto-terminal/

If using the ring terminals, what spark plugs are you using?

Have any of you used the “Sparky” style rubber boots?
If so, what plugs, and do you have enough clearance for the front cover?

Thanks.

Prepare to be boarded!

[Mumbles]

There isn’t much room under the front cover on a Zephyr or Light Four for clearance so you will want to run shorty spark plugs if you are going to use boots on the terminals. NGK plugs, with a screw on terminal, in either BM6A or BM7A would be a good choice as they are of the correct thread size and heat range. The screw on terminal will also allow you to use the original ring terminals to, if desired.

In a pinch, you can make a ring terminal by using the wires core. Strip off a 1/2″ or so of insulation and split the core wire into two strands. These get twisted around a nail or something to make a loop which then gets soldered to hold it together. And excess then gets nipped off. This works good with NGK’s as they have a screw on terminal. Champions don’t.

• This reply was modified 3 years, 11 months ago by Mumbles.

[Buccaneer]

Thanks Mumbles. Any idea what spark plug was originally called for in the later Zephyrs?
I’m only finding charts for the 1940 – 1942, calling for J10 Champion Plugs.

AC M44C marine plugs were in my Zephyr.
I did a little comparison with plugs I had around.

The vintage J-8J were just a hair shorter than the AC M44C, and the modern J8C were
the longest of the bunch.
The J17LM wins my shorty contest, but I’m not sure yet how they compare on the heat
charts to the others.
I wish I had the NGK plugs you mention to compare. Next trip to the big city I’ll have to
get some.

I like your alternative method sans ring terminals.
While looking thru the old Evinrude manual, I came across Evinrude’s ring terminal tool.
Probably not many of those “out there”.

Thanks.

Prepare to be boarded!

[Mumbles]

Later Zephyrs called for J6J’s set at .025 so the short NGK BM6A should be a good substitute.

[labrador-guy]

Buc, I did some searching and I found a heat range chart that compares the J6 to the J17LM. The 17 is one step hotter than the 6. Sending a picture, this is from a 1982 champion spark plug master application catalog. Don’t know anything about those NGK plugs. They are all good when they are working!

dale

Is a hotdog a sandwich?

[Buccaneer]

Mumbles wrote:

BM6A

The NGK web site says that the 5921 (removeable terminal nut) BM6A have been discontinued,
and to substitute with NGK 7421 BMR6A Nickel Spark Plug (also with the removeable terminal nut),
but I have no idea if the length changed, so I found some of the old BM6A’s on Ebay.

Prepare to be boarded!

[Buccaneer]

Dale, thanks for the chart. I saved it for future reference!
No reason those J17LM plugs won’t work for what little
I’ll be using the Zephyr, you can’t get much shorter,
and I have some on hand.
Also have the NGK’s on the way, so I’m covered!

Prepare to be boarded!

[Mumbles]

BMR6A code is broken downs as B being the thread, M for shorty Bantam plugs, R for resistor, 6 is the heat range and A notes a special firing end design. Maybe they are nickel plated on the end. Dunno. Sounds like the new replacement plugs are the same except they are resistor plugs.

Think I better call my auto supply in the morning to see if they have any bricks of the old BM6A plugs out back. I bought one a few years ago but don’t have any left.

[jcrigan]

Those small metal eyelets you get at craft stores works well for spark plug terminals. You may solder these to keep the single strands from sticking out.

[Buccaneer]

Mumbles wrote:

BMR6A code is broken downs as B being the thread, M for shorty Bantam plugs, R for resistor, 6 is the heat range and A notes a special firing end design. Maybe they are nickel plated on the end. Dunno. Sounds like the new replacement plugs are the same except they are resistor plugs.

Think I better call my auto supply in the morning to see if they have any bricks of the old BM6A plugs out back. I bought one a few years ago but don’t have any left.

Thanks for the “breakdown”. Glad I didn’t order the resistor plugs!
It sure is a struggle to “live in the past” with these old outboards!

Prepare to be boarded!

[Author]

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