What year is my cb 550 please

[Rolfbulmer]

Hi guys,
I have recently acquired a honda cb550F.
The V5 says it was registered in 1979.
The frame No. is CB550F-2113328
Engine No. is CB550E-1153025
My research makes me think it is an F3 from 1977
Could anybody please let me know if this is correct. Also does it look like the frame and engine are 'matching'.

[Nurse Julie]

Welcome to the Forum. If its an original 1st registered UK bike (ie, not a USA import) it can't be a F3 as we only ever had F1 and F2 in the UK model range. Also, if it is a UK model, its no good looking at USA engine / VIN numbers, which is what is generally found on the Internet. Is it an import or a 1st registered UK bike?

[deltarider]

There was no F3. It's an American 'invention': the US market is used to a new model every year, for marketing reasons, but Honda never produced a F3. If you want to identify your model exactly, there's p.4 in the Parts Lists: https://www.honda4fun.com/dwnload/Part-List/CB550/CB550-F2-Parts-List.pdf

[Bryanj]

Similarly it has to be late registered if 79 but there were a lot left in crates

[Rolfbulmer]

Thanks for the replies.
Nurse Julie: I believe it is a first registered UK bike.
Deltarider: thanks for the link - It would appear that the frame and engine number could be any of the options on the list on page 4, so confusing for me.
Bryanj: Yes, I thought that also, all adds to my confusion.

[Oddjob]

Any pictures of it?

It could be a K3 but wearing a lot of F parts. Pictures would show us if it is as there are a few differences.

[Rolfbulmer]

Hi Oddjob,
No pictures that would help as bike mostly in bits at the moment. The picture in my avatar is the most complete.

The USA forum have sent the below;

Hi and welcome.

The model guide shows it to be a '77 F2....

http://www.sohc4.com/cb550/cb550/#cb550f

[Bryanj]

Top of the carbs is one givaway, "P" shaped with a screw top and bottom is K3, Coffin shaped with a screw each side is an F

[Oddjob]

Check rear of swinging arm, if fully enclosed it's an F type, if it has removable end caps it's a K.

Tubular type rear brake lever K, flat type F.

[deltarider]

Important in that Part List is p.17 (clutch modification): https://www.honda4fun.com/dwnload/Part-List/CB550/CB550-F2-Parts-List.pdf

[Sesman]

What was the modification please? I can’t seem to see one specifically identified. Or,do,you mean the F2 differs from  the F1 and K models?

[Oddjob]

It's the central pressure plate Phil I believe, was modified after a certain engine number. No 6 and 7 on the list on page 17.

[Bryanj]

Is that the double steel plate in the stack Ken?

[Sesman]

Thanks, Ken. I’m guessing that’s item 6 changed to a 7? I ask as my clutch has an item resembling the ‘7’. Double sided as suggested by Bryanj.

[Sesman]

Thought so…it’s featured in the workshop manual.