Thanks for all the suggestions.
Mileage is about 37-39, hasn't changed since I bought the bike used in 2007.
It's an '01; just turned 20K last week.
Checked the vent hoses and all around the tank, there does not seem to be any leaks.
I have seen on this and other forums reports of a 'whistling' sound out of the gascap
when parked in the sun or on hot days. I have that sound which is quite noticeable after any ride
regardless of the temperature. I have been told that this 'venting' is normal for a Concours. After about 5 minutes, the whistling stops, but by then the garage is filled with fumes. It also stops if I open the tank but resumes within
30 seconds of replacing the cap.