I would put some die electric grease on the spark plug boot, and some on the rectifier box on the back right corner of the frame. That should cover the most common electrical problems. if you still continue to have the problem I think I would check the carb. drain line. does it take is a few moments to start running right after you come out of the water. It doesn't sound like yo go in deep enough water to have this problem this is just a shot in the dark.