Dave,
I looked quick and may have missed it but...
There have been a few people here who have reported leaving the petcock open and when they go to start the bike, the stored gas vapors and liquid fuel kicks back through the carb manifolds and detonates, blowing their airbox apart. Somone posted pics of it a year or so ago. Can't remember who.
I've only gotten a big bang once and the airbox is fine but it served to remind me that there are variety of reasons to turn off your gas.
BB
