Topic: What do the numbers on the cam mean? (CB750K)

[cookindaddy]

I have a bad cam (the journal at one end is badly burnt where the support post clamp died) which I would like to replace with a "new" old cam. Both my bike and the donor bike are 78 CB750K. My cam has the marking R9 on the body near the sprocket and the "new" cam has the marking R1 in the same place. Also, the R9 cam has the marking "M" and the R1 cam has "D" in the same place. I hope that I have attached pictures to this message correctly.

Do the markings mean that the cams are not the same (interchangable?)? Or are they factory info of some kind that I can safely ignore?

The donor bike has also supplied cam support posts and clamps that look really nice which I also will replace.

Thanks a lot!

[mystic_1]

The posts I've seen here in the past say that the R# numbers on the camshafts are just production information and don't indicate year or make of the cam.  Easiest way to be sure those cams are the same is to measure and compare, I think.

mystic_1