This is how I winterize my Yamaha. Fill up the fuel tank and add the correct amount of Sta-Bil gas stabilizer. Also fill up the oil tank. Start it up on land with the fresh water flush on it and run it for 5 minutes. With it still running turn off the gas and turn off the water. It should die out in about 30 seconds, during that time you should rev it up a bit to get the rest of the water out of it. after it cools down pull the plugs and shoot in some fogging spray, give it a crank. Remove and store the battery, coat the engine and everything else inside with silicone spray. Shoot all the cables and reverse bucket hinges with some Bombardier anti corrosion spray. Wash and wax it and let it dry. Go to the hardware store and buy some plastic sheeting to cover it with, then put the tarp on that. Don't use the regular cover as it leaks some and you could end up with some mold in there. Store it with the trailer nose raised up as high as you can so any water does run out the back. Trickle charge the battery once in a while over the winter and have a good one!