I finally got the ski back on the water. Same problem. Here are some additional notes:
It idles fine and goes through the water just fine at idle.
If I slowly accelerate it will speed up but after a couple seconds of increasing power it starts to "lose traction".
When idling and moving forward if I push the throttle down all the way it acts like a car on ice, it still moves forward at the idle speed, and the engine accelerates fine, but the ski doesn't speed up. I am detecting a vibration when that happens. Of course I am getting giving that description after only a few seconds of holding it wide open, I didn't want to break it worse than I already have.
I did run it with the back cover off and when I accelerate water comes out around the carbon ring.
I suspect something is out of alignment. The slight vibration I am feeling, and the water coming around the carbon ring both indicate that to me. Does anyone have any suggestions? If not I think my next step is to start taking things apart and inspecting them starting with the impeller and working my way forward.
Can I pull the driveshaft easily, or does that get into major surgery?
As a response to Mickirig's sand comment, I have a lift, and this ski does not get beached. I have only owned it 2 months, so no guarantees as to what happened before me. But now that I have it the ski is only at the cabin, and when we bring it to shore it goes on the lift. The good thing is that as I tear into it and replace things, I will know exactly what I have and how it will be treated. Of course my track record isn't very good so far!!!
For some background, I am 38 years old and play with old cars. I am by no means a mechanic, but I have rebuilt engines, done brakes, clutches, etc. My day job has me in the office a fair amount and doing handyman type work a fair amount. So I am not stupid when it comes to working on things, but I am not a pro either. This is my first jet ski. I bought it 2 months ago, so I am definitely still cutting my teeth.