THE OPERATOR STATED THAT HE HAD PROBLEMS WITH THE PWC RUNNING PROPERLY. HE STATED THAT IT STALLED AND HE WAS TRYING TO START IT BACK WHEN IT EXPLODED. THE EXPLOSION CAUSED  THE OPERATOR TO BE THROWN APPROXIMATELY 10 FEET IN THE AIR ALONG WITH THE JET SKI AND HE LANDED IN THE WATER HARD WHICH CAUSED THE BROKEN ANKLE. HE WAS TAKEN TO THE HOSPITAL AND TREATED FOR A BROKEN ANKLE. MECHANICAL FAILURE IS BLAMED FOR THE EXPLOSION.