Thought I'd offer some food for thought concerning petcocks.
A couple of weeks ago I started my '00 KLR, and right away I smelled raw gas. I got off the bike and began looking around, and noticed a fine jet of gas coming from the edge of the petcock. Shut down the bike, and ordered a new petcock from Kawa.
This brought to mind another incident with a petcock that illustrates the dangers they can present.
A while back I had just picked up a near-mint 1976 XS750D Yamaha (three cylinder) that I knew had been sitting for an awfully long time. It was in the dead of winter, and the temps were well below zero, but my unheated garage still was warm enough for working on the bike. The first step was to rebuild the carbs. I disconnected and removed the battery, unbolted the gas tank (which had only about a gallon left in it), then unhooked the fuel lines on the two petcocks. Immediately, one of them started pouring out gas all over the place. I reached behind me to grab a towel, and suddenly, whoomf! The bike and I were engulfed in flames. Apparently caused by a static spark due to the cold, dry air in the garage, and when I moved I must have touched something that caused the spark. I threw open the garage door and rolled around on the alley to put my clothes out, then grabbed the burning bike by the forks to pull it out of the garage. Of course, it tipped right over, and dragging the 760 lb machine across the concrete took longer than I had hoped. By the time I got it out of the garage and the fire department arrived, the bike was toast, but my garage only suffered some minor charring on the inside of the door where the flames reached as I was dragging the bike. Some second degree burns on my legs (the keys in my pants pocket got hot enough to bend) and some small areas of third degree burns on my hands left me with a painful reminder that you cannot be too safe when it comes to working with fuel systems on bikes. I know it's a long story, but I believe it's an important one.
Big Ray in North Iowa
1972 Yamaha DT250 (my first bike)
1975 Honda CB360 (my college ride)
1976 Yamaha XS750D (burned, may she R.I.P.)
1980 Yamaha 850 Special (went to new home)
1981 Yamaha 850 Special (former daily ride)
1982 Kawasaki KZ250 L-1 CSR (sold)
1996 Suzuki DS80 (my son's first bike)
2000 Kawasaki KLR650 (my new love)
2008 Honda CRF100L (my son's first "real" motorcycle)