Topic: '76 CB550 spark plug cap resistance

[Oddjob]

There’s a resistor to suppress period noise? Must get the missus one, she’s always cranky at that time of month 😁😁


No market would ever demand an inferior part, just not in a humans nature. Or at least I assume so.

[carnivorous chicken]

Just for the record, those are the prices for two.

Fraid not, that's each. It just indicates there are 2off each type. Try adding to cart and checking.

I have a set of the meatal shrouded caps that were fitted to the K1. They are 5k ohms.
My very low miles K0 has 7.5k ohms caps and wouldn't be surprised if they are original.
[/quote]

Right you are, my mistake. That is crazy expensive...

[denward17]

Went on a 10-15 mile ride today to make sure bike was running ok.

It seemed to run fine, with no issues.  I really could not tell much difference in the way it ran.


Checked all 4 plugs after it cooled, 2, 3 and 4 looked good being a light tan color, while #1 was still a little dark.

Will put some more miles on it and watch the plugs, may go to DR7EA on the next batch just to see if I can tell a difference.

Found an older thread from TwoTired who indicated that if you change to 5K caps, you should change to 5K plugs (R plugs) to match how the system was setup by Honda.  Mine did have 10K caps.

[Bodi]

No, not just for RF noise.
The 5/10/20K resistance is trivial for the high voltage coil output. Essentially the coil will generate an infinite voltage (theoretically, obviously not in reality) until the energy from the collapsing magnetic field finds a way out. The gas in the plug gaps ionizes and allows current to flow at whatever voltage is needed, maybe 10kV maybe more or less. This ionized gas has a fairly low resistance compared to the plug caps.
Once it's ionized and current starts flowing that current is limited only by the coil secondary, plug cable, and gap resistance if there's no cap resistor. A hot but very short duration spark is created across the two plug gaps.
But that short hot spark is not ideal.  A slightly "cooler" spark lasting longer is better able to ignite the mixture in a typical non-homogenous cylinder charge. The cap resistors limit discharge current, so the available energy from the coil takes a bit longer to expend.
There's a limit to how much resistance is beneficial. And the two plugs should have about the same cap resistance.
You do not want both resistor caps and resistor plugs a a general rule. This may work OK for normal riding but too much resistance can cause missing at high RPM and full throttle when cylinder pressure is extreme and it's harder to achieve a good spark.
Yes metal core plug cables with non resistor caps will work OK - usually - but the resistors actually do something useful. And they also reduce/eliminate interference in AM radio but who listens to AM radio or uses CB these days???
Potentially non resistor setups can cause severe interference problems with aftermarket electronic ignition systems as well, cross triggering the 1-4 and 2-3 coils. You do not want a spark when the intake valve is open in an intake stroke.
So... just use resistor caps and non resistor caps or vice-versa and stop worrying about it. Resistor plugs with resistor caps will likely be no problem but IMO that's not a good plan.
Original caps from the 70s are probably just at end of life. If they measure OK, and resistances roughly match (+/- 20% or so) don't worry about it. The more serious problem with many of these bikes is arcing from (old and decaying) plug cables to the frame or tank, this is worse when the secondary circuit has abnormally high resistance.

[Deltarider]

(sigh) Show me anything readable, anything, on this from outside this forum. Man, have I searched! What you've posted is just a warmed over clique of what other 'experts' have posted in this forum.
I have run my bike for some years with no (zero) resistance in the leads to the standard (= non resistor) sparkplugs and I swear on whatever holy book you want, that I have never ever noticed even the slightest difference, not in driveability, not in mileage. But maybe you can enlighthen us why the models for Canada needed that extra resistance (CB550K3 and CB650).

[fizzlebottom]

But maybe you can enlighthen us why the models for Canada needed that extra resistance (CB550K3 and CB650).

'82 CB650 here. I always read the FSM like it meant that the from 79-81, the Canada models called for non-resistor plugs and the USA models called for resistor plugs because of how the plug charts are formatted. I figured it had something to do with stricter US emissions standards but never put much more thought into it. The 1982 addendum only lists resistor plugs, leading to 10k total. All 650s prior to that were 5k for Canada and 10k for USA (or the other way around?).

[RAFster122s]

Don't feed trolls...

[Oddjob]

That may be the best post I’ve read for a while RAFster122s.

[Deltarider]

Come on, Oddjob, you with all that experience. Why are you so shy to enlighthen us on the wonders of extra resistance in the HT path? 

[Deltarider]

There’s a resistor to suppress period noise? Must get the missus one, she’s always cranky at that time of month 😁😁

At her age?! She'd better see a doctor.

No market would ever demand an inferior part, just not in a humans nature. Or at least I assume so.

You've missed the point. As far as headlights, the US wanted a level playing field. That's why all vehicles had to have the same inferior sealed beam headlights for decades.
Vehicles that had wonderful Cibié headlights like the Peugeot 504 were not admitted unless they bowed for the US rules. The pic below shows you the result. Not two inferior headlights, but four! Wow, isn't that great?! Hey, hey, hey, four is more than two, right? In the US consumer market it's always quantity that counts. More is better. You can even present them added resistance as a plus.

[Deltarider]

[...] I figured it had something to do with stricter US emissions standards but never put much more thought into it. [...]

I's obvious you didn't. Here is a 'thought' for you. The last model of the SOHC CB Four series was the CB650. Guess what... Honda fitted a CDI! How about that for spark duration?!
Re-edit: also read reply#71.

[Oddjob]

Come on, Oddjob, you with all that experience. Why are you so shy to enlighthen us on the wonders of extra resistance in the HT path? 

Discussing anything with a person who is convinced they are right and the rest of the world is wrong is like a broken pencil, pointless.

Plus what RAFster said.

[Deltarider]

Come on, Oddjob, you with all that experience. Why are you so shy to enlighthen us on the wonders of extra resistance in the HT path? 

Discussing anything with a person who is convinced they are right and the rest of the world is wrong is like a broken pencil, pointless.
[...]

That's what we in Dutch call a 'dooddoener' (clincher, knockdown argument). Come one, Odd job, enlighten us. Don't do it for me, do it for 'the rest of the world'.

[calj737]

Don't do it for me, do it for 'the rest of the world'.

The rest of the world is already enlightened. It is you alone that needs education and direction.

That’s what we call a “mic drop”. Oddjob owes you and others nothing. And I’ll accept Bodi’s very detailed explanation over your conjecture.

Go ride a bike.

[Deltarider]

Don't do it for me, do it for 'the rest of the world'.

The rest of the world is already enlightened. It is you alone that needs education and direction.

That’s what we call a “mic drop”. Oddjob owes you and others nothing. And I’ll accept Bodi’s very detailed explanation over your conjecture.

Go ride a bike.

Well, I'll be darned... Calj!! What a surprise... still reading my posts!

[fizzlebottom]

I's obvious you didn't. Here is a 'thought' for you. The last model of the SOHC CB Four series was the CB650. Guess what... Honda fitted a CDI! How about that for spark duration?!

That still doesn't explain why the 79-81 CB650s called for 5k in Canada and 10k in US (or the other way around), and then in '82 they all called for 10k even though they had the same exact CDI ignition system throughout the entire 4 year run. What is your insight on that?

[Oddjob]

Canada and the USA are 2 different countries, 2 different requirements for legal compliance, 2 different emissions controls etc

Most of the stuff Honda (and other manufacturers)were forced to do back in the mid 70s onwards were the result of Californias increasing obsession with emissions. Even stuff that didn’t get imported into the US suffered and still does to this day.

I’m not saying in any way that they were wrong btw

[Deltarider]

Who said emissions were involved? I have not read anything about this before reply #30* and #41**. Who made up that story? Any documents to substantiate this wild guess? Looks like the urban myth thickens.
* reply 30

I figured it had something to do with stricter US emissions standards but never put much more thought into it.

.
**#41

Most of the stuff Honda (and other manufacturers)were forced to do back in the mid 70s onwards were the result of Californias increasing obsession with emissions.

This is a perfect example of how the internet works and myths are born. Someone makes something up about emissions. Another interprets it as exhaust gas emissions and comments and from there all of a sudden it's a fact.
Resistance in the HT path of an ignition and EGA? Gimmie a break!
But I'll be a sport. Just show me a document, just one that substantiates what so far is a wild guess.

[fizzlebottom]

Dude. All I asked was why the CB650 spark plug listings in the FSM were different between Canada and US until 1982, even with the same ignition systems. Throw me some ideas. It either comes down to external pressure or engineering, and the first two that come to mind are "government made us do it" or "we figured out that it runs better this way".

So instead of just telling folks why they're wrong, why not offer a credible possibility.

[grcamna2]

Canada and the USA are 2 different countries, 2 different requirements for legal compliance, 2 different emissions controls etc

Most of the stuff Honda (and other manufacturers)were forced to do back in the mid 70s onwards were the result of Californias increasing obsession with emissions. Even stuff that didn’t get imported into the US suffered and still does to this day.

I’m not saying in any way that they were wrong btw

I like your position in this 'conversation' Oddjob.   
You are persistently patient. 

[Deltarider]

How about my patience? For how many years have I waited for proof. Please realise that no one took the matter more serious than me. I've searched and searched and found... nothing. I've asked around at the ANWB (our AA) and in professional workshops. All I got was sighs and/or a puzzled look, a shrugged shoulder and from the far end of that particular workshop a giggle.
Nevertheless I remain curious. Maybe you guys can explain what made Honda fit a CDI (known for an ultra short spark duration!) on the CB650?
And if it had anything to do with exhaust gas emissions, why were we all, pro's as well as amateurs free to play with our fully accessible air screws and other settings? Doesn't make much sense, does it?
It seems that in this forum my asking - which in science is the first step to move forward - is interpreted as blasphemy and/or insubordination. Are we in church then? In the army?

[grcamna2]

How about my patience? For how many years have I waited for proof. Please realise that no one took the matter more serious than me. I've searched and searched and found... nothing. I've asked around at the ANWB (our AA) and in professional workshops. All I got was sighs and/or a puzzled look, a shrugged shoulder and from the far end of that particular workshop a giggle.
Nevertheless I remain curious. Maybe you guys can explain what made Honda fit a CDI (known for an ultra short spark duration!) on the CB650?
And if it had anything to do with exhaust gas emissions, why were we all, pro's as well as amateurs free to play with our fully accessible air screws and other settings? Doesn't make much sense, does it?
It seems that in this forum my asking - which in science is the first step to move forward - is interpreted as blasphemy and/or insubordination. Are we in church then? In the army?

I recommend you seek answers from the manufacturer;someone who had worked at Honda?
They were the ones which built these machines.
When you eventually find someone who gives you a reason for the purpose of the resistors,if they will explain it in detail,please share this information with the forum.
I would certainly like to understand it.

[Deltarider]

I recommend you seek answers from the manufacturer;someone who had worked at Honda?
They were the ones which built these machines.
When you eventually find someone who gives you a reason for the purpose of the resistors,if they will explain it in detail,please share this information with the forum.
I would certainly like to understand it.

Gamma, with all due respect, I have reported what I have learned from the technical department of Honda The Netherlands and from Honda France innumerous times.
In the early 80's I've asked the chief of Honda's Technical Service in the Netherlands, the guy that receives annually Honda mechanics in the field to educate and instruct. I've asked him why I had a seemingly original plugcap that read 9K and the others were 5. He informed me they all should read about the same and advised: 5kΩ. That was common practice then and it is now. There is nothing to add.
And in the French manual that heas been composed in close cooperation with Honda France we read:
En cas de remplacement, il est important de monter des antiparasites ayant une resistance inferieure à 8000Ω sinon il y a perte de puissance d'allumage.
In translation: over 8kΩ, no good.
Mind you: it is the only manual that mentions the resistance in caps (p.84). In all automotive literature you'll find... nothing, not even in Steinbuch's 8 volume standard work.
I'm no expert, but I can calculate. Effectively over 20kΩ in a secundary circuit is a lot. Therefore I personally will not risk reliabilty for a, so far only theoretical benificial effect on spark duration. Until proven otherwise, I recommend 5kΩ in either plug or cap, but not in both*. But I invite anyone to experiment and show proof.
*In Holland I know of two workshops that have advised to abstain from R plugs as far as the old SOHC Fours and there's a UK mechanic that works on these machines on a daily basis who advises the same.
I find it sad that the community here is so uncritical and what I find particularly alarming is that there are quite a few members here that never miss the occasion to beat the drum of how many years they've worked in workshops and all but, in spite of that experience, never dare to even ask. They prefer to blame me. For what? Well, for asking. Can you believe it? 

[Oddjob]

First of all I never said emissions was the reason why they got different plug caps, just that different markets had different emissions levels and still do to this day. It's common knowledge within the trade that California started the whole emissions thing, back in the 70s the level of smog in places like San Fran was so bad you couldn't see the city from overlooking hills, just the tops of some of the buildings. Plenty of photographic evidence to back that up and I'm sure some of the US members can remember it. So each vehicle that was sold in California had to pass new emission laws, that meant the manufacturer had to prove how much each vehicle was producing conclusively. They were going around with huge bags attached to vehicles that the exhaust was venting into, this was then analyzed and a figure of pollution was given, if it was below Californias level you could sell the vehicle, if not you couldn't. Pretty sure I'm not the only one to remember that.

All this type of info was passed on by trainers at Honda when I attended training courses, we talked about lots of things, the reason why Honda did things in a certain way was certainly discussed. Differences in carb jets between the 500/550 was discussed and the reason given was because the engine had to run leaner to pass the new USA tests, it's also why they fitted the recycling system from the crankcase venting.

I've explained all this multiple times to Deltarider but he refuses to listen, tell him you've seen evidence in written Honda documents back when you were in the trade working for a Honda/Yamaha/Suzuki main dealer and he refuses to accept it. Eventually you just have to conclude that if the evidence doesn't fit with what HE thinks it should then he'll just scream "prove it". Anything he says should be taken as concrete evidence with no proof needed.

Now just to upset him, I have MANY years in the trade, he has none. Who would you rather believe? 

Oh and last thing, you spoke to the head trainer in Holland and he told you loads of stuff, prove it.

[RAFster122s]

Trolls believe what they want and arguing with a troll is like arguing with a fool, they will beat you with their experience arguing, not with their experience