I got a seadoo gt 97 787 engine and won't start. i charge the battery complete and nothing. i put a new batt and is the same thing. check voltage toi the starter nd is good. i remove the spark plgs and engine crank's good. i remove the starter and is burn, i replace the starter ski start good, i run the ski and stop for 1 week and when i start again no start and show 12v low like before. and no crank. i need the help i don't know to much for the jetski is my first pwc. thanks