Tonight I cranked my bird up to head home and had a neutral to leave it idling. I walked away from the bike and left it idling for 2 3 minutes as it was cold outside. All of a sudden I started to hear a metal on metal noise coming from it. It has 24,700 miles. When I pull in the clutch the noise sounds exactly the same, no change. I wrote it home two and a half miles and it performed great I can still hear the metal or metal noise throughout the ride but could not tell anything different in performance. I'm thinking transmission or something with the clutch but not sure. Any thoughts or comments would be appreciated. Thank you.