At 23K you're past the time I would have waited to adjust the valves. Your bike could well need some other maintenance by now as well. Depending on how you ride you could have burned up some brake pads by now, loosened up your head tube bearings, and a bunch of not-so-minor things. You might want to consider changing brake fluid and coolant too. Type of use and the environment cam play a big role in maintenance needs. A good mechanic can advise you. It's time to send it to the shop.
Those valves are sort of a pain, but I did my own. It took me most of the day the first time to get under all the plastic and learn how the beast is put together. 3 out of 4 exhaust valves were .001 tight (not much and within spec.). I felt better knowing. Next time it won't take half that much time (depending on how much I forgot).