exhaust issue

2001 Challenger with twin 717s. Last time on the water the left engine started losing power and wouldn't rev past 5000. On the trailer it has trouble starting. Once started it won't idle, only run with throttle part way up. After starting the hose, water starts squirting from the curved exhaust...

I just bought a 2007 sea doo 180 challenger se with the 215hp. When I bought it the boat had only 2hrs on it. I took the boat out later that week to the river and it started fine. As soon as i went 5k-6k rpms it flash exhaust warning and made a continuse beeping noise until I shut off the boat...