Over the years, For Hondas I've used 15,000 and 30,000 depending on the owner's manual. After the first adjustment, though... they don't drift much.
Last 4 years or so, they have been recommending at 105,000 miles or "when noisy". A small amount CR-V owners may have burnt exhaust valves MAYBE because they let them go too long.
Here's two cars that said wait until 105,000 miles:
1999 CR-V: Adjusted at 30,000 miles and still runs like I just did it at 51,000. This car gets the shakes on acceleration if you don't have good adjustment. (some call it wobble, you feel it in the calves of your legs!) I had this condition for probably 5,000-10,000 miles before the 30K adjustment I did.
2002 S2000: Adjusted at 7,000 miles, had a minor but noticeable improvement on warm idling.
So the first valve adjustment should come at 15,000 miles on the Hondas, even the newer ones based on my experiences. After that you can probably wait 30,000-60,000 miles if you do good mainenance otherwise. Especially if you take your time and get each and every valve exactly where it needs to be and use a torque wrench to set the adjuster lock washer. Don't wait for the valves to get noisy, consider how rough the car's idle is an earlier indicator.
[ February 11, 2003, 10:38 PM: Message edited by: S2000driver ]