Well, my stock petcock has gone the way of all (flesh?), replaced with a Raptor petcock as so many here have done. My thanks to the many here who have offered their advices on the subject, with special thanks to txsizzler; after watching his YouTube videos 2-3 times, by the time I actually did it I felt like I'd already done it. MOST useful for the faint of wrench.
I concluded I needed to make the switch even w/o doing Serowbot's petcock test, based on the bikes behavior - spontaneous silence followed by reluctance to start. When I pulled the vacuum line this afternoon, sure enough, there was gasoline therein, a sure sign of vacuum petcock failure. On a 2007 with just over 3000 miles on the clock. (!)
Anyway, to my question: While I didn't smell any gasoline in the sump, is it's presence in the vac line cause for alarm?