Last weekend I had been on the lake all day used 3/4 tank of gas was headed home and the engine started cutting out and wouldn't go any faster than idle speed. It was acting like it had ethanol in the gas. The last time I used gas with ethanol I added some treatment and ran all the gas out. Filled up twice since then (Ethanol Free) no problems. Now this, I checked the water filter it was clean, I just changed the fuel filter a few weeks ago. Could the fuel guage be messed up, or what?