my pemex station , barra de navidad, has no water in it -- however, once in the
tanks, used , then sat, there is water in
tanks.
i have been advised by a fellow cruiser here in mazatlan to check my fill cap for tiny holes at either end of key slot. (mfg defect, compounded by age and probable corrosion)
it seems fuel goes into tanks clear, clean and without water , if it is from pemex. then as heavy rains tend to get everywhere and inside everything, the water came into their tanks and mine via these holes. currently they(my friends) sillycomb their fuel fill top so NO water enters when the heavy tropical rains fall and accumulate, and they have experienced no more of that which i have experienced more than once , and of which others have written--- heavy accumulation of water in the fuel tanks.
i emptied 30 liters of yukky looking cloudy water and 40 liters of weak smelling varnishy fuel from my foul tank.
i plan on replacement of my fuel fill cap. sight unseen. then i will then inspect it and fotograf it to verify this.