should I adjust my valves?

[GoOn3]

My 400ex has a full Yoshi pipe, jetted, and K&N. I have never adjusted the valves and it's a 2000 model. Someone told me that if it's been that long, don't adjust 'em, it will cause more harm that good because the valves have been seeted in place. Any input on this?

[hondarider2006]

Mines a 2000 and I adjusted them not to long ago. Seemed like it did some good to me:)

[sickmojave]

If it was mine I would adjust them. ;)