After suffering through the infamous 2002 CRF valve problems, I over reacted and bought a 650r. I heard stories of 10-15,000 mile engine life on these things when my CRF needed to be freshened up after 2-3 thousand miles. Maybe I'm cursed but I only got about 1800 miles on the 650 before one exhaust valve started tightening up fast. I normaly check valves every 300-400 miles, but started doing longer adventure rides (800-1000 off road miles) I'm an ex honda dealer mechanic with a long history of building engines and racing. I am a fanatic about maintenance, I always have a clean filter, and never hit the rev limiter. In short,.. I just don't deserve this! Enough whining, here's what's happening. Valves were rock solid and hardly ever changed for the first 1800 miles and 4 valve checks. I went on a week long 1000 mile ride, and both intakes loosened .001, the left exhaust tightened .001 and the right exhaust tightened up .007!! (from .009 to .002) Well maybe it was a fluke, and at least it wasn't zero. Yes the crank was positioned right, and I checked them cold. I set everything back to specs with the exhausts at the wide end .009. After an 850 mile rocky mountain adventure I checked them again. Same story only worse. This time three valves hardly moved but the right exhaust was WAY tight. I'm talking two full turns of the adjuster just to get any clearance. Surprisingly, it still ran and started OK?? The problem valve is on the right, so it can't be related to the decompressor. I occasionaly use a lead replacement additive to help cushion the valves. The right threaded adjuster is visibly farther out than the left one,.. like maybe .060-.080, which tells me there may have been a problem from the beginning since I only backed it out 2-3 turns in an attempt to restore clearance? I only have 3600 miles now. Anyone else have valve recession problems or heard of any service bulletins?? I still have the Neway valve cutter set from the 450 fiasco, any chance the seat angles are the same?