Brake rotor date code

[rick-chuck]

Just going through the Parts wanted page, and a member needs a disc. Checked my small stash and no luck. I've been in need of a Sep. '74 disc and noted That one I have is a 9 N. The N month doesn't exist. Obviously the letter is not a month indicator. Confusion x2. I've been looking for a 9 H. What SHOULD I be looking for? Help, Rick

[compo z1r]

Rick according to my info N is on the list u can work it out from here ok

[Philippe]

Hi Rick
it's normal you're confused. So was I when I started, so don't worry.
It's all explaned in Compo's answer.
The number means the year, the letter is a 4 week code. The Japanese used the Showa date code, that means the number of years of the reign of the Japanese emperor. 1974 was the 49th year of his reign. 1975 the 50 th year. They only used the last number so you can see 9 for 1974 and 0 for 1975...
The letter indicates the 4 week period of production during that year. A means the 4 first weeks of the year, B the second 4 weeks...
As you can see in Compo's explanation they didn't use all the letters. Why not ??? I don't know.
I hope it becomes a bit clearer for you now.
Just a warning, if you start paying attention to those details you might become a rivet counter like me
GrtZ
Philippe

[rick-chuck]

It's too late... an original front mudguard's inner mounting bracket has 13 rivets holding it on! Help!