Does anyone know how to check a petcock from a 1985 vf1000f? If I shake the tank I can get fuel to come out of the exit tube but when I shake it again, it plugs. There is nothing rattling around in the tank, so I suspect something in the petcock. However, there is no way to get access to it.... that I know of. Any ideas? Can someone also confirm the vf1000f is a gravity fed fuel system?