jet drive not thrusting

I have a 1995 Dynasty Sport Jet 120 that has been totally overhauled. After getting the engine to finally fire and run, once in the water the jet drive starting slipping. Finally, it quit thrusting all together but the engine would still fire right up. Checked the shaft and impeller and they both turn when the engine is running, but still no thrust out of the jet drive. Any suggestions on what I might do or what could be causing this problem. TIA.

Adam

 

Is the intake blocked?

If the impeller is intact and turning, my first guess would be a blockage on the intake side.

 

Not sure what you mean by intake side. I have taken the intake grate on bottom of boat off and found nothing blocking it.

 

That is what I meant

That was my guess.

 

If you still have the problem I would sugest checking if anny coupling is sliping.

Maybe the impeler is rotating only when it's unloaded and once loaded some coupling will slip.