I have a 2002 Sea Doo Islandia that I've owned for 2 years. I took it down for the first time after sitting for about 5 months. it started right up, but when the throttle was Advanced about 2500 RPMs the warning alarm would sound in the engine would retard. Of course this happens regardless if it's in forward or reverse. I confirmed the oil level was good and the blower was on. what should I check first?