SEADOO 1997 problem? HELPPP?

i HAVE A 1997 speadster boat and when I put it in the water it wont go over 10mph and then one of the engines will die. I think the engine dying is just a problem with the gas that I can figure out. What I have no idea on is the speed thing. I was told that it might be a wear ring but the dealer i called wanted $500 to fix that and said it could even be something bigger so they would have to fix that first.

How can I tell if the wear ring is bad enough that it needs to be replaced?

There are very small cuts into it like that you can hardly even feel, but there are parts where it looks like the impeller is further away then it should be almost like the ring has become soemwhat oval but not really/

Does anyone know if thi might actually be the wear ring or is it more likely a motor seizure problem?