a lean condition on one cycl could of caused this, or a bent crank and the engine was running out of time on that cycl. My guess would be lean condition on the one cycl. This can be caused buy bad jets in the carb or a vacume leak in the engine. being a 96 i would guess it has a few hours on it and will need a overhaul, and the carbs gone threw. I have always sent my carbs to
PURELY TECHNICAL online with they do a great job and have never had a carb related problem from them, i send all my customers carbs their also, just can't say enough about these guys and their reasonable in their pricing. Good luck. You can go to
New Jet Ski Parts and Used Jetski Parts - Jetskiparts.com to get a breakdown of your ski it works well for figuring things out.