My K1300GT had the valve clearances checked last year at around 44,000 miles, as the plastics were off for new throttle bodies to be fitted. Whilst the work was undertaken a little earlier than required by the service schedule (it had covered around 11,000 miles since last check, which was also carried out early) I was told that no adjustments were needed.
I was charged just one hours labour to check the valves and replace spark plugs with the fairings etc. already removed.
Incidentally, the stick coils were replaced as a precaution at 44,000 miles, as they showed signs of "bulging" slightly. I was told that this is often the case, at higher mileages.