As my earlier note indicates, I had a loose outer rotor ring on the right side of my '04 FJR. I could hear a clunk going over bumps, etc. When I first took it in to a local Yamaha dealer, the service manager looked at it and tried to tell me that this was normal, that "believe it or not, Lee, the looseness will actually tighten up as you ride the bike". I looked at him and said "Oh give me a break, check the rivets holding the outer ring onto the rotor, the rivets are loose and I can spin them with my finger". He did and never said another word--they took the bike in and replaced the rotor under warranty.
Lee in the Mountains of Northern California 8)