The problem was you thought about putting a rag in there. If you weren't thinking it, the bolt would not have been dropped :smile: .
I'm in the middle of a valve adjustment myself, and I did not use the rag. I got one in there now while I'm awaiting the shims from Fred, hopefully to avert my son from dropping an action figure down there.
One time a dropped a screw (not KLR), I heard it hit the ground and could not find it for the life of me. It turned up a couple of hours later in the laces of my shoe.