it could also be the bolt that holds the tank down at front, I once noticed mine missing and quite a few km's later and having thought I had lost it found it sitting on top of rocker cover, if is that bolt it should have a washer with it, I since put a rubber washer under it so it wont work loose again, but that bolt should be Chrome/Stainless Steel so it is also possible as others have said that it is off the Radiator Shroud (there are a couple of bolts out of sight at top underneath shroud that are holding the metal grills in place) or the black plastic covers on the space between tank and headstock