It all started when I hastily adjusted my valves awhile ago on my "new to me" 2000 xr650r. I probably did not get TDC correct and activated the autodecompressor (my best guess at least). immediately after, I got a loud clicking or clanking noise from the front right exhaust valve audible at all rpm ranges. When I say it was loud I mean I was embarrased to ride my bike. The bike still ran well, and was asymptomatic of any problems other than the noise. But lets face it, thats enough look at another solution. I had since re-adjusted the valves and was sure I did it right. The noise stayed. I am now preparing the bike for a three day trip to Death Valley, and let me tell you, I don't want anything to grenade on me in the Valley of Death. So I took the bike to a couple of friends who have been wrenching on things for many many years. As I would cycle the flywheel to find TDC we could hear the offending clanking noise and feel the hit if we put our finger on the top of the adjusting nut of the front right valve. One friend suggested that I might have a broken inner valve spring which was causing the valve to seat weird due to just one spring doing all the work. So the decision was made to remove to rocker cover and see what we could see. All looked well, none of us has any experience with the decompressor set up like the xrr has ,so we played with it, cycled the flywheel, probed the springs with the blades of various tools, and visually checked all components. Since all looked well we figured it was just a "quirck of the bike". The repair manual compared against the bike did'nt show anything out of the ordinary. I put it all back together and let the rtv gasket sit overnight. When I fired it up in the morning, the sond was gone, the bike sounded like a sewing maching (compared to the day before.) So I don't know what happened exactly, Im just saying excessivly loud valves do not have to be put up with. Any ideas what we did to rid the bike of the loud clanking noise?