This just happened to me as well. I have this foamy white residue built up in the throat of my carb. Clean it out and its fine for about 10-15 minutes, then starts bogging in the water and runs lean when out (Revving out of control). I also found the same residue on the outside of the carb around the fuel pump. Does this mean I have water in my tank or maybe the carb is sucking water from splashing around in the hull? I use outerwears to keep water out of the carbs. Any suggestions?