Unfortunately, nobody makes the stainless valves yet. Kibblewhite is still about 8 weeks away from having any. I should know, I've lost 4 sets of vales in the last few months. The last set I only got about 150 miles on. I don't think the valve issue has been completely addressed by Honda for '05. Ther may still be issues. One of the problems is the cheap titanium Honda uses for the valves. Pro Circuit sells a higher quality Ti valve but they cost big bucks.
Another theory has it that the problem is with the cam...the ramp is too severe and it sends the valves slamming back down on the piston. Anyway you look at it you're screwed.
That's why mine is for sale...I'm going to buy a 2 stroke! :bang: