1998 Seadoo Gtx Limited Died On Water No Start

[ElijahEvo]

This is a vehicle me and my friend ride he took it out and said it had sluggish acceleration and made a clunking noise when he killed the engine, we changed the spark plugs checked oil and fuel then took it for a test run, the engine had a hard time idling, VERY slow acceleration, then on accelerating was making a whining/hissing noise, a minute later engine stopped accelerating and slowly died out, the engine won't restart just one loud clunk and the engine shook like the starter engaging.

I have since pulled the spark plugs and tried to turn it on and the engine wouldn't turn over, (unsure how to try and turn it over by hand) spark plugs were oily obviously, and a bit white. Battery reads 12.7 v. Thats all I know, I've worked on go karts/buggies but never a seadoo before. Any help on where to start and the likely cause would be very appreciated. The oil injection tank was full and I've been using seadoo pwc oil.

 

[jim downing]

Sounds like the engine is toast. To find out:
At the back end of the engine you should be able to find the shaft from the engine to the jet pump. This shaft is about 7/8 inch in diameter. It might be covered with a plastic shield that you have to remove. Using some big pliers or pipe wrench see if you can rotate the shaft.
If it rotates freely (with plugs out) then the engine is not frozen up. Good. If not, then I would suspect the oil injection pump failed and your engine is toast. Did the engine overheat (long solid beep)? If it can be manually rotated then check the compression.