[timberfoot]

. The previous owned apparently loosened the muffler clamp when he was installing his crash bars then forgot to tighten it back up.

I check my muffler clamp bolt for tightness from time to time. I have found it to be a bit loose on more than one occasion, more often than any other bolt or nut on the bike. So, I advise to check the muffler clamp bolt, and others every now and then.