Who adjusted valves?
 

If you did, what was mileage?

There should be no need to adjust the valves, the engine should be equipped with hydraulic lifters.

It has solid lifters and shims. My 80 Kawasaki kz1000 has the same adjustment.

Valve Clearance Adjustment
Remove the camshafts.

Use compressed air to remove the shims that require replacing.
Blow compressed air between the shim edge and bucket to dislodge the shim.
Use the following formula to calculate the required shim thickness.
Original shim thickness + measured clearance - desired clearance = required shim thickness.
Apply a light coat of engine oil to the replacement shim(s) and install.
Install the camshafts.