1997 GTX Won't Turn Over

[jaboto4]

I recently acquired a 1997 GTX Seadoo with a 787 rotax engine. When I first put the craft in the water it would die if you didn't keep its RPM's above 1000 and it would bog down around 5500rmp. After the test run I cleaned the rave valves and took it for another test run. The higher RPM bogging seemed to be improved but still not back to 100%. During one of the test runs the engine dropped rpm's fairly quickly (around 2-3 seconds) and died. After it died the starter would make a load clunking noise and would not turn it over anymore.

I have pulled the spark plugs, removed and inspected the cleaned rave valves, removed and inspected the starter, and removed the propeller and still can't seem to turn the engine over by hand. I don't beleive the engine has seized as it didn't come to a sudden stop but now I'm not sure. Any advice would be appreciated.

 

[POPPS]

Usually, mostly, unfortunately, with your symptoms, you have an engine failure. It could be top end, or lower end, ( rotary valve, rotary valve gear, or crank bearing). If you pull the plugs and they have a gray coating on one of them (cylinders never seize together), then you definitely have a top end failure. And in most cases, it's due to fuel delivery issues, from the fuel pickup circuit, or the carbs ( lean fuel delivery).