This is disappointing, but the manual does not say how do check or adjust the valves that I can see. The manual is well written I think with lots of pics. They show many major procedures, even removing the heads, valves, etc. Maybe it's so easy they didn't bother? Seems odd.
If the service is $200 as I read some where, if my math is right and its a 4000 mile interval once it's broken in, do you realize that's going to add about $3.50 cost to every gallon of fuel we use? A nickel a mile. 70 miles to the gallon. I hope I can figure out how to do it myself.