I get that once in a while on my 1000. Sometimes it's the left side, and sometimes it's the right. Seems to last for a while and then go away, or change sides. It just loses that "crisp clean" exhaust note. It hasn't affected the way the bike runs, it just sounds different sometimes.
I gave up on trying to figure it out. Maybe it's a fuel thing, or we're listening too close.
2006 GL1800 (Brutus Maximus)
1978 GL1000 (White Trash)"My Effort"
The White Trash Album
....Sharing some thoughts...."Venting GL1000 Rotors"
Hole templates for front and rear (45 holes) and how to use them"Side Stand Indicator Light"
For those of us who can't remember..."GL1000 RearSets"
Photos, CAD drawings and instructions (click "No Thumb" and then "Download Doc")I'd like to apologize ahead of time.