Check the leg oil, there is a big screw at the bottom near the prop, you will need a BIG screwdriver, undo it a bit NOT FULLY or you will get oil everywhere, and see what comes out, it should be nice oil, if there is any gunky white there could be water getting into it. Worth changing the spark plugs for the minor cost. When you start it up on land do you see water coming out at the bottom of the leg, you should do as well as the squirting, if its not then seek professional advice because I don't know what I am talking about