I'm trying to start my 760 twin carb Yamaha Wave Venture for the season. The battery checks ok, but when I press the start button, I hear a simple click. By feeling and listening, I narrowed it down to the relay in "the box". Using a multimeter, I read 12.25v. from the battery. When I press the starter button, the opposite post reads only 5.53v. Also, the digital readout dash is not coming on. Also, last year, the jet ski would be running under power then suddenly it would begin dieing off. Sometime I could feather the throttle and it would eventually return to normal speed, sometimes it would die. Usually it would restart and run fine. I would appreciate any help on these topics, thanks.