Some people are experiencing problems with the cam chain tensioner. It manifests itself as an intermittent knocking sound. There are videos of this on u tube. (unfortunately I cant get my computer to copy a link) If you get this issue take it up with Honda and DO NOT accept an explanation "that's normal" or "they all do that". They should know about it. Remember the warranty expires in a year so if you only put like 1500 miles on in that time you might develop the problem after it expires. CRF Only sells a replacement tensioner for $90 which presumably has been redesigned to fix the problem. But I don't know that only speculating. Any further info or experience you may have please post. Thanks!