Topic: The CB500 Four - Any Appreciable Differences?

[Dr. Frankenstein]

Is there any difference between a '71 - '73 CB500 Four vs a 1975 CB500 Four? There's an (allegedly - I haven't put eyes on it yet) 1975 CB500 Four that popped up near me - I have TWO already - a '72 and a '73 waiting for restoration - but would a '75 be a 550...? It LOOKS like a regular 500, but I'd kind of like to add a 550 to the stable - are there any outward differences?

[seanbarney41]

Yes there are differences...the main question is what does the seller actually have?  Is it a 72/73 built 500 titled as a 75?  Or has he mis-identified a built in 75 550 as a 500?  Could also be built in 74, in which case, some strange and controversial transition  models have been seen but no one really knows what was original and what was part swapped.  The main identifier is clutch actuation...which side of the engine is it on?

[Dr. Frankenstein]

Looks like the clutch is on the right. The clutch basket, that is...

[bryanj]

The 550 was all 500 cycle parts with a 550 engine, the big visible outward difference is the clutch adjuster
500 has the big sloted adjuster in the sprocket cover
550 has external operating arm on the clutch cover

UK never got the 550 till the F1and K3, we kept the 500K1 until 1976, european direct sales were i think the same.
There was a 500K3 in certain markets which was a 550 with 500 block and pistons.
Engine number should define what it is

[bryanj]

Just to add the VERY early 500K0, which seem to be US or Japan only had different gearchange detents which were modified after about 6 months i.e. about September 71.
Apart from that there were very few mods to the 500 throughout its run

[jlh3rd]

Is there any difference between a '71 - '73 CB500 Four vs a 1975 CB500 Four? There's an (allegedly - I haven't put eyes on it yet) 1975 CB500 Four that popped up near me - I have TWO already - a '72 and a '73 waiting for restoration - but would a '75 be a 550...? It LOOKS like a regular 500, but I'd kind of like to add a 550 to the stable - are there any outward differences?

well, for the U.S., there is no '75 500 four. A '75 in the U.S. is a 550. Bottom line for identification are frame and engine #'s.

[Oddjob]

I'd imagine the clocks would be the biggest obvious difference, the K0 and K1 both got the smaller clocks like the CB250, the K2/3 got the larger clocks like the 750.

My BIL has a 76 (registered) CB500 but it's just a 72 CB500K1 that didn't sell for a few years. That may also be the case for yours.

[jlh3rd]

lots of threads on inaccurate "model year" registrations. You can't go by the registration claim.

[Oddjob]

I didn't say you could, however in the UK we didn't get the VIN plate with the year of manufacturer on it till 76. So we tend to refer to bikes by the model number, like K1 or F2 etc. That doesn't mean to say it can't be a late registration, eg unsold stock being sold cheaply due to other models coming out. In the UK we get specific letters or numbers now to denote the year of registration, a 72 bike for example would be a K reg, 73 would be L, they'll both be 500K1 though. We didn't get the K0 or the K2/3,  there are a few UK 500K0s though but they were grey imports from Europe.  It's confusing as we speak in different terminologies.

[jlh3rd]

and I didn't mean "you" as in personal and I'm not talking any country other than the U.S. And very aware of U.K. honda model designation differences.

[Oddjob]

Not a problem, I didn't take it personally, I wasn't aware you knew about the way the UK does things. It's different but it works for us, as I suppose the year thing does for the states, confusing though at times.

[Don R]

 My 1973 cb500 turned out to be a 1972 after I wrecked it and needed parts. The dealership owner was asked to sell me the latest model by my brother who worked there. He told us it was the newest one. It was, but only the newest one that he had in stock.
 It went through a couple headlights in short order, the third one lasted years.

[jlh3rd]

Not a problem, I didn't take it personally, I wasn't aware you knew about the way the UK does things. It's different but it works for us, as I suppose the year thing does for the states, confusing though at times.

all good...It was the D.O.T in the U.S. , supposedly lawsuits, that wanted a "year"model designation because of just what the post says above....older unsold bikes being sold as the current year. Us guys here in the states were used to car model year. Up until 1974, honda sold bikes by model designation as in the UK. They could sell the same model for years.

[Deltarider]

The solution to end all confusion is simple: go to the "paper" parts lists and learn how Honda defined their models by the engine- and framenumber. It's either a CB500(K0), a CB500K1, a CB500K2, or a CB500K3. All these models - no exception! - have a suffix that indicates the market that model went to, the socalled 'area code'. Only by interpreting that suffix you can learn that for instance the CB500K2-ED, -F, -G, which was marketed in 1976-7 (!) was quite a different model than the CB500K2-A. These parts lists give the better overview and are all here: https://www.honda4fun.com/materiale/documentazione-tecnica
CMSNL offers a nice feature to look up what specific part was also on other models. I can't believe that after all these years, I still have to repeat this. 

[jlh3rd]

there's no confusion. Everyone except maybe newbies understands honda model designation. That's not what we're talking about. Show me where anyone denies UK and other export countries that honda specific model could span multiple years.
We're talking the difference in the U.S. concerning registrations and model year. Not parts . OFFICIAL U.S. Honda policy.
It seems some people, even after repeating it over and over don't understand that Honda adopted model year  designation for the U.S. in 1973 and implemented it in 1974. That's a fact, not my opinion.
The cb500 K2 was NOT marketed in the U.S. in 1976....but the 1976 cb 550K 550 four was. Officially it is a 1976 550k. In the U.S., it is not a K2. That is official honda. They dropped K1,K2, etc after 1975. It doesn't matter what you wanna believe, or what CMS says, or honda4fun...In the U.S. it is a 1976 CB 550k. and confirmed only by frame/engine #'s....AND the frame will say "1976 model"....as does the manual....not K2...
and that's what the title and registration should say, 1976 Honda CB 550K.....period.

[Oddjob]

Must say that I was a Honda mechanic for many years and I did not know that. Very informative and does explain a lot of things I question on the site.

Although saying that, why then are there a NUMBER of thread titles which say stuff like "I bought myself an F1 or K2 etc" which sort of undermines your statement a little, not a criticism BTW, just saying that some people still use model designations even in the USA. In the UK we never speak about years unless it's relevant, oddly we seem to value the engine/frame number more than say the USA, for instance you say you ask for the newest the dealer has, for us, if they is no difference between the newest and the oldest numbers we'd ask for the oldest as it tends to be worth more, frame number 1 for instance ( IF it was available, which it never was but is a good example) would be highly desirable. I have a friend with frame number 7 for his Kawasaki 500 triple, it's worth a LOT more than the later numbers just because it was the 7th built, no other reason.

Not sure if this applies in the USA but in the UK after the bike reaches 40 years of age it doesn't pay road tax or need an MOT (a yearly inspection), so an early frame number would be desirable as it can reach the 40 year mark faster than later ones. Anything like that in the USA? You don't ask, you don't learn as they say.

[Deltarider]

there's no confusion. Everyone except maybe newbies understands honda model designation. That's not what we're talking about. Show me where anyone denies UK and other export countries that honda specific model could span multiple years.
We're talking the difference in the U.S. concerning registrations and model year. Not parts . OFFICIAL U.S. Honda policy.
It seems some people, even after repeating it over and over don't understand that Honda adopted model year  designation for the U.S. in 1973 and implemented it in 1974. That's a fact, not my opinion.
The cb500 K2 was NOT marketed in the U.S. in 1976....but the 1976 cb 550K 550 four was. Officially it is a 1976 550k. In the U.S., it is not a K2. That is official honda. They dropped K1,K2, etc after 1975. It doesn't matter what you wanna believe, or what CMS says, or honda4fun...In the U.S. it is a 1976 CB 550k. and confirmed only by frame/engine #'s....AND the frame will say "1976 model"....as does the manual....not K2...
and that's what the title and registration should say, 1976 Honda CB 550K.....period.

This happens to be an international forum and the international community would like to know what you're talking about, so they can give the best advice possible.

[jlh3rd]

there's no confusion. Everyone except maybe newbies understands honda model designation. That's not what we're talking about. Show me where anyone denies UK and other export countries that honda specific model could span multiple years.
We're talking the difference in the U.S. concerning registrations and model year. Not parts . OFFICIAL U.S. Honda policy.
It seems some people, even after repeating it over and over don't understand that Honda adopted model year  designation for the U.S. in 1973 and implemented it in 1974. That's a fact, not my opinion.
The cb500 K2 was NOT marketed in the U.S. in 1976....but the 1976 cb 550K 550 four was. Officially it is a 1976 550k. In the U.S., it is not a K2. That is official honda. They dropped K1,K2, etc after 1975. It doesn't matter what you wanna believe, or what CMS says, or honda4fun...In the U.S. it is a 1976 CB 550k. and confirmed only by frame/engine #'s....AND the frame will say "1976 model"....as does the manual....not K2...
and that's what the title and registration should say, 1976 Honda CB 550K.....period.

This happens to be an international forum and the international community would like to know what you're talking about, so they can give the best advice possible.

Sure. Use "K1,2....", "F0,1,2..." designation for other countries it seems as ya'll didn't use model year . For U.S. imports ,use model year 1974 and up, with the understanding that "K0,1,2.."..."F0,1,2..." was phased out by 1976.
That's all, not critical, just correct. Makes a difference sometimes.

[jlh3rd]

Must say that I was a Honda mechanic for many years and I did not know that. Very informative and does explain a lot of things I question on the site.

Although saying that, why then are there a NUMBER of thread titles which say stuff like "I bought myself an F1 or K2 etc" which sort of undermines your statement a little, not a criticism BTW, just saying that some people still use model designations even in the USA. In the UK we never speak about years unless it's relevant, oddly we seem to value the engine/frame number more than say the USA, for instance you say you ask for the newest the dealer has, for us, if they is no difference between the newest and the oldest numbers we'd ask for the oldest as it tends to be worth more, frame number 1 for instance ( IF it was available, which it never was but is a good example) would be highly desirable. I have a friend with frame number 7 for his Kawasaki 500 triple, it's worth a LOT more than the later numbers just because it was the 7th built, no other reason.

Not sure if this applies in the USA but in the UK after the bike reaches 40 years of age it doesn't pay road tax or need an MOT (a yearly inspection), so an early frame number would be desirable as it can reach the 40 year mark faster than later ones. Anything like that in the USA? You don't ask, you don't learn as they say.

no offense taken. I understand with decades of using misunderstood facts...and then throw in the internet, facts can be...buried....It's not critical, and the world isn't gonna end by saying a U.S. 1976 550F is an "F1". Just repeat'n what honda says.....fwiw...

In the U.S., some states , like Pa., let you register a bike/car as an antique after some years...25 I think . So inspection and registration every year is not needed. However, you aren't supposed to drive the vehicles except to and from car show activities, and parade type activities.....
Part of our road tax is paid as an add on tax per gallon of gas....

[Oddjob]

Oh we aren’t as restrictive on usage as that. Basically we can use it whenever we want, for as long as we want, as often as we want. We call them historic. They are also exempt from pollution charges like in London. They also tend to be cheap to insure but can be expensive to run due to mpg not being great in the past. Tbh it’s about the only way you get some of your money back after an expensive restoration 😁😁

[RAFster122s]

The US 74 CB550K was never known as a K0, that is something that came later as a designation parts applied to designate the first of the model line.

[Deltarider]

Correct. One could opt for writing: CB550(K0).

[jlh3rd]

as was with the first 750, not a K0.
had to change that avatar...😂

[Stev-o]

So, it turns out his bike is a JDM....

[Dr. Frankenstein]

Wow - quite the conversation! Good to know all that; but as I asked in another thread here, is there a different manual for JDM's, or will the 'CB500' manual work?