My son's 2006 TTR 50 was slow returning back to idle so I asked at the shop what to do. They steered me in the right direction and told me the valves were likely tightening up and to check them. I did and sure enough, they were tight. So I adjusted the valves and the bike now returns to idle and runs great with one significant problem - the valve noise is horrific. I can hear him behind me when I'm on my bike. I have the manual for the bike and followed the directions (to the best of my very unmechanical abilities) to find TDC and set the valves. I am using standard feeler guages I picked up at Pep Boys and I set them according to the specs in the manual. Does anyone have any suggestions? I don't think the valve noise inside the head should be this loud. Maybe I didn't really find TDC? This is the first time I've ever busted into a motor with valves, so I'm guessing there's something I'm missing here. -Thanks.