How do you winterize 1989 Kawasaki tandem sport jet ski?

To winterize a 1989 Kawasaki tandem sport jet ski, start by draining the fuel tank and adding a fuel stabilizer to prevent degradation. Next, flush the cooling system with fresh water to remove any salt or debris, and then drain it completely. Remove the spark plugs, add a few drops of oil into the cylinders, and turn the engine over to lubricate the internals. Finally, store the jet ski in a cool, dry place, and cover it to protect it from dust and moisture.