Headstock number

[Popstar]

The plate on the headstock of my bike has 6/71 on it does that make it a KO or K1 ?

[Bryanj]

Yes it does



But seriously many other things make the difference,
Put up pics of both sides and i will tell you

[Seabeowner]

Mine is about 7/71 and about 6600 higher number. They certainly were churning them out.
I think just about all at that time went to the USA and maybe Japan and will be K0.

[Popstar]

Thanks,this one is a US import,and yes that’s some difference in production numbers, it’s no wonder they conquered the world.i wonder what month production started.

[Bryanj]

I can answer that it was Feb 1971 as i own frame number 36

[Bryanj]

Frame number brgins with a 1 so its a K0, according to theAmerican Honda ID book

[Popstar]

Thank you.

[AshimotoK0]

Mine is about 7/71 and about 6600 higher number. They certainly were churning them out.
I think just about all at that time went to the USA and maybe Japan and will be K0.

Production wasn't without  headaches though as Honda used quite a few components in the transmission from the CB250/350K twin and without adequate oil feed to some components plus gear shifting issues ...so, before mods were done, they had serious problems .... so serious that  when they were selling unsold K0s alongside the 1st K1's there was a Class Action lawsuit in the States against Honda and certain owners could claim the agreed settlement fee, I believe.

I think CB500-1018727 was the last K0 that didn't have the mods incorporated in production. (see attached Bulletin kindly provided by Bryan on here.

[Bryanj]

That mod gave better neutral detent, better shift drum location and, in theory, less clutch slip and also had a little oil feed scoop in it.