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Want to Buy early Honda CB Spark Plug Cap

Pridanc

Pridanc

Well-known Member
Joined
Dec 4, 2020
Total Posts
63
Total likes
11
Location
LIBERTY HILL, TX, USA
Folks,
As I'm doing the final assy on a long winded early CB project, I noticed that the Spark Plugs Caps I have are not correct. Lets not go into why, after years, I just noticed that OK?

Looking around I've found one but need another. Be aware there are many versions that are very close out there but the early bikes have a shorter "high tension lead" limb. Take a close look at the picture. The area between the HT wire rubber cap and the body of the cap (trunk?) that slips over the plug is quite short. The most common ones, that are close in appearance from Honda, have a longer limb.


Correct Plug Cap.jpg

I only need ONE but happy to buy a pair if that is what it takes.

Once I'm done with this, there will be a write up posted here and the part will be seen there.
Thanks in advance!
 
Last edited:
Flyin',
I can't thank you enough for looking and tossing out suggestions. As you point out the "limb" is too long.

Your suggestion of purchasing a pair of these is a great one, and one I've considered, but I'm not ready to toss in the towel just yet. II just got a response from someone who has one without the HT lead grommet and am considering it, but I'm still not at that point where I'm willing to settle. There is always that "who is going to know the difference"? Sadly, I will know, and that makes me crazy. A sickness I think!

I'll keep looking for now but again, big thanks for taking the time to help. All the best, PC
 
You could try shortening the "limb" on a longer one. It'll be covered by the boot.
Are you going for a concours restoration?
If so I can understand the need, otherwise I wouldn't want to use 50+ year old plug caps.
 
Boosted, did not know of them so will reach out to them. TYVM for the suggestion.

Cycleranger, I'll say concours with a minor twist (as everyone will be able to read soon enough and simultaneously shake your head saying "you did what?" all while chuckling) as its a long story but has been a fun one for me.

And I do appreciate your good points over the potential failure of such old stuff however, parts made as these are can indeed fail, but can also last a life time. Fingers crossed for the lifetime. I have been contemplating your idea of two new caps with me shortening the limbs but for now, I'm holding out. (no wonder this is taking so long right? Obstinance has its upsides...)

Many thanks to all. If I find one I'll holler to let everyone know job done. All the best.
 
Pridanc said:
parts made as these are can indeed fail, but can also last a life time. Fingers crossed for the lifetime
Click to expand...
While I can appreciate your interest in originality, this involves an electrical part that, in fact, does not last forever even under the best circumstances. Resistor plug caps have been known to double or even triple in resistance over time, and if true that would cause you performance issues once you start riding it.
 
Ancient,
I'm aware of what you guys say but know good ones exist. I have one in my hand that is good.
However, the more you guys push, the more I may need to look at repros with an eye on modifying the limb to have the cap appear as it did in '61.
Like you guys say, there's nothing quite like new.
As always, many thanks to everyone for chiming in. Warms my old heart.
Stay well, PC
 
Pridanc said:
Ancient,
I'm aware of what you guys say but know good ones exist. I have one in my hand that is good.
However, the more you guys push, the more I may need to look at repros with an eye on modifying the limb to have the cap appear as it did in '61.
Like you guys say, there's nothing quite like new.
As always, many thanks to everyone for chiming in. Warms my old heart.
Stay well, PC
Click to expand...
Hang in there. Eventually you will find that match but you need something to use until it shows up.
FYI, I'm running ones even older than that on my Dream. They are gray and don't have any "Hm" markings. As long as they don't get a crack that shoots a short to the head or the little spring clip inside that grabs the threaded tip of the plug doesn't loose it's grip, they'll last forever.
Jjq6l62l.jpg
 
Ballbearian,
Thanks for the words.

As a way to help folks see what came on my 1961 CB72 , and I think most others, (notice how I leave that wide open?) my cap is a non resistance type and very simple in construction. See below.

The pointy brass thing gets screwed into the cap's large end just as it is placed here. As you screw this brass thing up into the body of the cap, the point pierces the solid wire HT lead you previously pushed into the short stubby off shoot at the top right of the body.

Original 61 plug cap.jpg

The odd looking clip fits into the groove of the brass thing and is what presses onto the spark plug thread (tiny cap of plug is removed) for a tight connection.

Short of breaking the bakelite of the body, this kind of cap will last almost indefinitely. As years went by, along with the introduction of some high faluting electronics, it became common/necessary to go to a resistance type ignition for electronic noise suppression. Since this bike is pre-historic (like me), it was without.

Thanks again for the help and suggestions everyone!
 
Pridanc said:
Ballbearian,
Thanks for the words.

As a way to help folks see what came on my 1961 CB72 , and I think most others, (notice how I leave that wide open?) my cap is a non resistance type and very simple in construction. See below.

The pointy brass thing gets screwed into the cap's large end just as it is placed here. As you screw this brass thing up into the body of the cap, the point pierces the solid wire HT lead you previously pushed into the short stubby off shoot at the top right of the body.
Click to expand...
THIS is why we always ask for pictures. Having never worked on any of the early '60s bikes which were all gone by the time I got to my first Honda shop in 1970, I was not aware of the earlier style like this with no resistance built in, and a lot of typing would have been saved if only that picture had been posted in the beginning of this discussion. Thanks for the clarification.
 
Pridanc said:
Ballbearian,
Thanks for the words.

As a way to help folks see what came on my 1961 CB72 , and I think most others, (notice how I leave that wide open?) my cap is a non resistance type and very simple in construction. See below.

The pointy brass thing gets screwed into the cap's large end just as it is placed here. As you screw this brass thing up into the body of the cap, the point pierces the solid wire HT lead you previously pushed into the short stubby off shoot at the top right of the body.

View attachment 27818

The odd looking clip fits into the groove of the brass thing and is what presses onto the spark plug thread (tiny cap of plug is removed) for a tight connection.

Short of breaking the bakelite of the body, this kind of cap will last almost indefinitely. As years went by, along with the introduction of some high faluting electronics, it became common/necessary to go to a resistance type ignition for electronic noise suppression. Since this bike is pre-historic (like me), it was without.

Thanks again for the help and suggestions everyone!
Click to expand...
Thanks, I've not seen this design. The old grey ones use the course thread (like a wood screw) straight into the side leg and up the middle of the HT wire.
 
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