Topic: Finally...! A CB550 Four!

[Dr. Frankenstein]

I've been searching for a CB550F for quite a while, after reading all about the improved engine performance and clutch over the CB500F, and FINALLY found one! This popped up on FB Marketplace a few days ago and only set me back two Franklins...one thing that made my eyes pop though was the odometer: 99503! I mean, Holy Mileage, Batman! Could that be right?? The guy had it advertised as an '84 CB554' which I don't think exists - or if it does it doesn't have those lines that a classic 550 does - but I know a 70's 550 Four when I see one, and I was right...it's a '73 with what I think is a pretty low serial number. Had to exert some effort getting it into - and especially OUT of - the truck; I had some help loading it but had to download it myself - not particularly fun with a super-tight rusty chain, which I cut off and it rolled a lot better - but finally got it into the garage. Yes, it has a healthy 'patina' on it  but it's pretty much all there except for the center stand, filter, side covers and the air box (which I already have)...but NINETY-NINE THOUSAND miles on it?? Can that be right...? Anyway - enjoy some motorcycle porn...the plan is to tear her down completely like I just did with my CB500 and go through everything to see what's what - probably in the spring, the garage gets too cold in the winter.     

[Gurp]

That tank is beautiful for my style and my favorite color.
Honestly compared to the stuff I see my way that's a wonderful project!

Sent from my LE2127 using Tapatalk

[Kelly E]

Your bike is a 74' CB 550 K0, I have a 74' CB 550 K0 with a 6/73' production date with the serial number of 1000449. In the US 74' was the first year of the 550.
Yours looks better than what we started with. My motor was on the floor with the top end off.
It turned out okay but took a while.

[bryanj]

Thats actually a CB550 K1 i think which is a 500 with a 550 motor and RH rear engine mount plate.
All the 500 parts will fit.
Even the tank is the same with a different paint job!

At least it has the sensible carbs not the K3 PD type

[jlh3rd]

you have a 1974 CB 550   (cb550KO) Freedom green metallic. U.S.
The build date is 10/73, build date does not designate a model year. There is no 1973 550.

[Kelly E]

you have a 1974 CB 550   (cb550KO) Freedom green metallic. U.S.
The build date is 10/73, build date does not designate a model year. There is no 1973 550.

My K0 was originally Boss Maroon. I still have one of the busted side covers. My buddy picked it up for me when I was on vacation. I was surprised by the low serial number. Mine has differences from the DR's like the non-locking gas cap. Because of the low serial number I didn't alter or cut anything off the frame. The only thing I cut was the seat pan, but it still opens on the original hinges and the seat lock still works.

The DR has a great start to resurrect, it should be fun.

[jlh3rd]

yep. The non-locking gas cap was an original factory part. The story goes that it seems in a collision as the rider gets catapulted forward, parts of his body could contact the push tab thus opening the cap. So I further understand that whenever a bike came into a shop, the cap was changed out with the superceded new locking cap......something like that....

it's a good find.

um...are you looking for a maroon side cover?

[bryanj]

The "lock" was a 400 four part and was the replacement for the catch, the cap stayed the same.
You can now no longer buy the original catch from Honda only the "superceeded" part number of lock which any key fits

[Deltarider]

One of the differences between an original CB550(K0) and a CB550K1 was that the former still had the smaller type blinkers the CB500 had...

[jlh3rd]

yep...also now see the tank is a K1 scheme, candy jade green? ....so wonder what the motor #is...
a used  bike.....never know what unless the #'s are run.

[jlh3rd]

Thats actually a CB550 K1 i think which is a 500 with a 550 motor and RH rear engine mount plate.
All the 500 parts will fit.
Even the tank is the same with a different paint job!

At least it has the sensible carbs not the K3 PD type

looks like it's a '74 KO frame with '75 K1 parts....if it's a U.S. bike

[jlh3rd]

"..but NINETY-NINE THOUSAND miles on it?? Can that be right...?"

well, it appears the bike is kinda a mixed bag. Speedos can be easily swapped.
However, the patina of the speedo and tach seem to match so I'd say they are at least "a pair" . But that doesn't mean they came with the bike.
Your frame tag says '74 KO model, but the tank and probably the entire front end is a '75 K1.
for your purposes I guess it doesn't matter...
what's the motor #?....also, I think the frame # is stamped on the left side of the neck which should match the tag...just to be sure....
the price was right.

[denward17]

Green faced dials?  Weren't they just on the '76 K2 model?

[jlh3rd]

dark green on the '75 K1.....light green on the '76 550K

here's a comparison of his and my '75 F's which were dark green...
so maybe his are '76 ?

[Dr. Frankenstein]

Motor number is CB550E-1011000...the neck number matches the ID plate - CB550-1011041

[Deltarider]

Motor number is CB550E-1011000...the neck number matches the ID plate - CB550-1011041

Then... page A3 here: https://www.honda4fun.com/dwnload/Part-List/CB550/CB550-K0-K1-K2-Parts-List.pdf informs you yours is officially a CB550, informally known as CB550(K0).

[jlh3rd]

you have a 1974 CB 550   (cb550KO) Freedom green metallic. U.S.
The build date is 10/73, build date does not designate a model year. There is no 1973 550.

yep ...previously posted...except he's got K1 parts...candy jade green tank...

[Oddjob]

The "lock" was a 400 four part and was the replacement for the catch, the cap stayed the same.
You can now no longer buy the original catch from Honda only the "superceeded" part number of lock which any key fits

Still available Bryan, I've bought a few over the years.

https://www.ebay.co.uk/itm/232902085563

[HondaMan]

Well, I dunno...with that much patina, maybe it WAS 99K miles?
Rode hard, always put away wet...

I seem to remember Crazy PJ rolling over his 550 in a post here long ago?

[bryanj]

Yes still available, even pattern when in stock!

[Deltarider]

When I bought my CB500, it was quite common these bikes would do 160.000 kms (which equals a ton in miles) without a major overhaul. Mine has done over 140.000kms now and still has its first pistons and primary drive chain. In my archives I have an article in which the owner of a CB500 was interviewed. At the time of the interview his CB500 had done 220.000 kms and the engine had not been opened yet. His secret: to ride it every day all year round to his work and to have the service done by a Honda dealer.
Recently I've heard about a GL1000 Wing with no less than 650.000kms on the odometer. The Honda mechanic that opened the engine, judged replacing the rings was all it needed. Pistons were still fine.
I don't know what goes on in the UK site. It seems they're at the primary chains, crank journals and gearboxes all the time. It is almost as if everybody infects the other. 

[bryanj]

I only quote what i have actally seen, not reported.

Primary chains on the 500 can, and do, wear into the main oil galleries in the lower case if the carbs/servicing is not spot on, I.E. the engine is not smooth.
I have worked on a 750 with over 120,000 miles on it where bores, pistons and rings were all well within Honda tolerance.

Since resurecting my Van Norman boring bar i have found that 500/550 rarely clean at 1st os (0.25) due to barrelling in the liner, and i have yet to have in my hands an ovaled cam cover

That is most of the common things

[HondaMan]

Since resurecting my Van Norman boring bar...

Bryan: how well do you like that Van Norman bar for boring these? I've considered getting one myself.

[bryanj]

You need the table and adaptor rings and the smallest i can doo is the 500, the 944 bar wont go less than 55mm so no 400, 350 four or small stuff.
You need to get one cheap or have a lot of boring to do.
944 spares and cutters are readily available from India so you can keep it goind