I'm probably done riding for the year, so I figured I'd check my valve clearance on the Z1, after the recommended 5,000 mile interval. All in all, not too far off. The outer exhaust valves were perfect, the inner ones, were a few thousandths tighter than the minimum spec. On the intake side, they were all in spec, but both valves on the mag side were close to the minimum spec.
When I have a high and low spec., I like to set it right in the middle, so I'll re-set the 2 intake valves, as well as the 2 exhaust ones. I ordered the necessary shims, and will re-assemble later this week. The camshafts need to be removed to change the shims, so I wouldn't recommend the average person tackle this job, unless you're comfortable with taking apart the top end of a double overhead cam engine.
I would assume that most of the clearance change would be over the first 5,000 miles, and I doubt that it would change much from here on out, but I'll check them again after 10,000 and see.
I know there are some Z1s out there with over 10k on them. Anybody with any valve stories?