Have You looked?
Get under the boat and look at the hole. Thats a low pressure area that means vacuum. That hole will suck trash off the bottom of the waterway(lake river whatever) and pump it out the back. That trash acts like a sandblaster and wears out everything it touches. Like Your Impeller and the inside of the Pump.
Seadoo designed a ring that fits very close to the impeller that will wear instead of the pump housing = "wear ring". It can be replaced quickly and easily. As the wear ring wears away, water leaks from the back side of the impeller(high pressure) to the front side(low pressure) and creates cavitation.
Whipping air and water is not good. It will not cool the motor properly.
Your motor get its cooling water from the high pressure side. Also the low pressure side will suck air from any where it can =air thinner than water.
Remember looking in the hole on the bottom of the boat? That shaft that goes through the boat bottom into the engine compartment has a seal that keeps the water out and the air in.(Carbon Seal) If the rubber boot that pushes the carbon seal tight against the stainless collar on the shaft loses its push, the low pressure or vacuum will suck air through and You have cavitation.
Use the search tab at the top of the page to learn how to repair these problems. I think You will have no trouble if You have worked on cars and bikes. You may consider becoming a Premium Member. It will let You have access to shop manuals.
Good luck and keep us posted.
