Europa-List: Water corrosion?

[Richard Iddon <riddon@sent.com>]

I have just emptied my Bing carb bowls (Rotax 912S) and found a white
liquid watery deposit, separated from the petrol, in the bottom of one.
When I emptied it out there is an area of corrosion in the bottom of the
bowl. I have also cleaned the fuel filters and found a similar deposit
in one and this also has attacked an aluminium collar.  Is this likely
to be just water or have I got something more nasty in my tank at some
point?

Richard Iddon G-RIXS