Rich...he specifically states there was never ANY fuel in his tank.
Naaaaah, that didnt happen !!!!! In a desert with normal dewpoints at 30-40 deg. of less, it would take hundreds of years for a cupfull of water to accumulate in an EMPTY motorcycle tank (1-2ft. cu. ft). If there was thermally driven mass transfer (heat/cooling cycles of the tank), then the same mass transfer would equilibrate BACK to the atmosphere - net equilibrium =~0. The same reason that the WWII Saharan debris is still in the SAME condition as the day its was destroyed. --- very 'doubtful'.