I have a 2006 GL1800 with 22,000 miles that was running perfect and then started tapping on one side. I took it to a Honda dealership and they checked out and found a valve keeper had got out of position and the valve fell into cylinder. No damage to piston but they are covering under warranty(extended). I have never heard of this on a Honda with so few miles. Has anybody else had any experience like this? I know Honda recommends checking valves at 32,000 miles. Please respond if anybody has had this happen.