What's the difference between the CB500 K1 & K2 models ?

[McCabe-Thiele (Ted)]

The CB500 seems to have a lot of model variants in a short space of years 1971-74 is there a Dummies Guide to the differences on our site here?

Do they share the same engine or frame were there any important changes to internals such as gearboxes etc?
Is the cam chain tensioner a better design than the 400?

[mickwinf]

basic engine and frame the same with minor changes and improvements all through the run. also differences between different markets but no major changes until the 550 came along in 73ish in USA and 75ish in UK ( gearbox mainly )

[Oddjob]

Biggest difference is the clocks, they went from the small version to the same size as the 550 later had. A good improvement in my opinion as the clocks on the 500 are frankly awful, they slope away from the rider especially if he's flat on the tank as I used to be when I was younger.

Paintwork changed as well, the black panel on the tank went and a flash appeared in it's place.

[Trigger]

You also had the 500K0 1971. Differences depend on what market you are trying to compare, UK, USA, Europe, Japanese ?
Depending on markets, Clocks, indicator stems, seats, tank colours, switch gear, tail lights, rear mudguard, handlebars and so on 
 

[Bryanj]

All official UK bikes were K1, except the press bikes, everything else was an import plus even the K1 has different parts in other countries e.g. clocks were inclined more to rider but still small type, different holes in rear mudguard and light mounting to suit, huge rear light etc.
Only majour engine change was gear detent system as early ones were not so good and clutch but that was early on in the run. Camchain tensioner mech is better than 400 but can still be knackered by ham fistednesd and needs proper use, generator has slightly more output

[Oddjob]

The early 500s had 200w generators but it was soon superceded and went down to 150w.

[deltarider]

For the European continent this link shows the differences: https://www.honda4fun.com/faq/generali/400-cb500-differenze-tra-k0-k1-e-k2. (scroll down). Note that the CB500K2 [ED, F. G] aka CB500K2 GENERAL EXPORT marketed in 1976-7 differed from the CB500K2-A which was marketed in the US in 1973. CB500 models for UK were a bit poorer: black parts where other markets had chrome, ugly tail light support, etc.

[Trigger]

All official UK bikes were K1, except the press bikes, everything else was an import plus even the K1 has different parts in other countries e.g. clocks were inclined more to rider but still small type, different holes in rear mudguard and light mounting to suit, huge rear light etc.
Only majour engine change was gear detent system as early ones were not so good and clutch but that was early on in the run. Camchain tensioner mech is better than 400 but can still be knackered by ham fistednesd and needs proper use, generator has slightly more output

There was a few more UK CB500K0's than the three press bikes that came to the UK Bryan. I have some Honda documents to show that there were UK 500K0's but, not a lot of them. There was a fair few that were sent from Holland and the clocks were changed but, they are easy to spot as, the pilot light plate was different and the right hand switch gear was different. 

[mickwinf]

Ted, if you are thinking of buying a 500 it is more important to find a bike suitable for what you want rather than the exact model. The early K0 bikes usually are a little more expensive as the first of any new bikes tend to be the most sought after by serious collectors, however the k1 or k2 bikes are probably a bit better as they have the improvements made by Honda over the life of the model. Also the parts that are unique to the rare ones are harder to find and very expensive. Do you want a full restoration or a bike in good nick? American imports often have good chrome, etc which keeps parts bills down a bit, but UK bikes fetch a bit more money, at the end of the day they look and ride pretty much the same so its personal choice. Another possibility is a 550, early US versions look like the 500 but with better gearbox, and later f1 and f2 also a good buy.

[Bryanj]

I have heard of the dutch ones and back in the day we must have had a K0 where i worked as the side panel had the transfer below the 500 badge which no body could find a part number for, that was black transfer on a gold panel damaged in accident. I eventually found a part number a few years ago in the japanese parts book i found

[Oddjob]

When I was at a Honda course I asked the main man there about the K0 and he told me ONLY the 3 press bikes were officially imported, one of each colour. 1 was written off by a magazine, one was scrapped but one is still around somewhere, or it was in the mid 80s.

[philward]

Also, from a precious post enquiry by me about fork efficiency, the KO, K1 and early K2's use the 450 forks - which aren't as good based on feedback from my post responses (early 550 forks?)