Before I added the in line filter, whenever I removed the float bowls, I would always have a fine sediment in the bowl, along with a few globs of water .
Since the addition of the in line filter, I have not seen any of this in the bowls .
I think a source of water in the fuel tank can be attributed to a deteriorated rubber seal on the fuel cap .
When you wash the bike, or it gets left out in the rain, the water puddles around the cap, until enough has accumulated to run down the drain in the filler area .
I replace this seal about every 5 years, the hot environment I reside in, is pretty tough on rubber parts .
But, it's something to check every now and then .
I remove the fuel tank every 2 years drain it, then leave it out in the summer sun for an afternoon or two, to evaporate any water that may have accumulated in there .
But with temps in the sun for a few hours the fuel tank is in the 160 F (71 C) range, I need gloves on to handle it .