VIN & Engine Mismatch?

[marssafari]

Just looking for some help in identifying the age of my bike.
The bike was imported into the UK in 2016/17, I think, from the US. For my V5C/Title the bike is registered as a 74' CB550 and the VIN plate states "MFD in Japan by Honda Motor Co., Ltd: 7/74". Although I had a look into the VIN and engine serials and neither seem to match the '74 date.

VIN Serial Nº: CB550-1203482
Engine Serial Nº: CB550E-1084002

From the model guide, it seems the frame is from a '75 CB550K1 and the engine is from a '76 CB550K2. So why is the dating '74?
Any help would be greatly appreciated!

[Bryanj]

Because a bike BUILT late in 74 is a 75 model as they were on ships for a lot of weeks and then in transport across the US (a big place) to get to dealers. Honda frame and engine numbers never match and engines are very difficult to date and people in US would sooner throw in a salvage engine than repair what they have.

[Nurse Julie]

To me it looks like that VIN plate has been tampered with. The plate should also be positioned on the headstock if a USA bike (edit...sorry, it is on the headstock now i have put my glasses on !!). Also, frame and engine numbers never, ever match on old Hondas

[marssafari]

To me it looks like that VIN plate has been tampered with. The plate should also be positioned on the headstock if a USA bike (edit...sorry, it is on the headstock now i have put my glasses on !!). Also, frame and engine numbers never, ever match on old Hondas

Sorry - I rotated the image. The plate is on the headstock

[marssafari]

Because a bike BUILT late in 74 is a 75 model as they were on ships for a lot of weeks and then in transport across the US (a big place) to get to dealers. Honda frame and engine numbers never match and engines are very difficult to date and people in US would sooner throw in a salvage engine than repair what they have.

Ahh okay - that makes sense! And so the dating of the title - is that correct or should it be '75? And when there are mismatched engine/frame dates, does the dating change? Is it based on the engine's age or the frame's?

[Nurse Julie]

I wouldn't worry about it. As long as you have a V5 that shows the correct VIN and engine number as they are on the bike, thats all that matters. As Bryan says, its probably had an engine change sometime, or even a frame change or both.

[Nurse Julie]

Because a bike BUILT late in 74 is a 75 model as they were on ships for a lot of weeks and then in transport across the US (a big place) to get to dealers. Honda frame and engine numbers never match and engines are very difficult to date and people in US would sooner throw in a salvage engine than repair what they have.

Ahh okay - that makes sense! And so the dating of the title - is that correct or should it be '75? And when there are mismatched engine/frame dates, does the dating change? Is it based on the engine's age or the frame's?

Always on the frame number (VIN)

[Bryanj]

Always on chassis(vin/frame) in UK but some US states issue title on engine number no idea what happens there if engine changed.
Give me time to find my Honda issue id book and i will see what that says.

[Rob62]

Does the number stamped on the frame headstock match the number on the VIN plate, and does it look as if its not been tampered with? If so then you can happily trust the VIN for the bikes age.

[JamesH]

The numbers suggest you have a CB550 K1 with a CB550 K2 engine fitted.

Definitely check the VIN stamping on the LHS of the headstock matches the RHS vin plate. It does look like your vin plate has been removed and re-attached with pop rivets (the original rivets were twist ‘hammer’ rivets with a much smaller head diameter).

[marssafari]

Hey all, thanks for all the help/clarification - much appreciated!

@Rob62 & Jamesh_sussex - The VIN stamp matches the VIN plate, it must have been taken off to powder coat the frame.

[JamesH]

Hey all, thanks for all the help/clarification - much appreciated!

@Rob62 & Jamesh_sussex - The VIN stamp matches the VIN plate, it must have been taken off to powder coat the frame.

That’s great news.

[royhall]

VIN plate has defo been off at some point it's wrinkled, probably had the frame repainted?