Kz or Z1

Ever since I got my bike I thought it was a kz because the side covers said KZ900 but looking at the title the first letter and number is Z1. Now I am wondering if I have been wrong. Also my headlight switch has a po marking in the middle and the book does not show this on the kz wiring diagram.Can anyone shed and light on this subject as how to tell the difference.All the parts I have bought have been for a Kz but I guess most will interchange.

I think all the engines in the KZ900 or Z1 line all Started with the Z1 number sequence. 1976 was KZ900, 1975 and prior was Z1 although all were designated Z1 on the engines. Could be on the frames too, I'm not sure, but if you have KZ900 on your covers you have KZ900 and if you have 1976 you definately have a KZ900. As to the PO thing, all my KZs have it and it does absolutely zero. Don't know why it is there except maybe as a designation for "position" of "off" or "on"??

Ok I found the topic in the other part of the forum that tells the place to look up the serial number to match with what I have and it looks like I was right, this is a kz. Since I just orders a bunch of parts I feel better now. My serial # is zi50xxxx