I am having problems with a friends GPR & we have been chasing a cavitation/slip on hard acceleration from idle(stopped). It just seems like the ski can't get traction for about 5-6 seconds & then it takes off. I have always suspected the prop shaft hose letting air in to the tunnel under acceleration. Is this a possibility?

We have done all of the pump seal kits & sealed everything up good with 4200. We also installed a New Solas impellor. We have done the pump sealing 3 times. The first time we used regular waterproof silicone, so that wasn't right. The next time we used "Right Stuff". That was probobly OK, but since the problem was still there, we did it again with 4200. Everything is sealed tight on the bottom.

The prop to wear ring clearance is around .014 & the wear ring looks almost new. The Solas prop is new & all splines were in good shape(no wear).

This leads me to believe that the only place the "cavitation" is coming from is through the driveshaft hose. I have read that the OEM hose is weak & on hard acceleration a vacuum is formed & the hose can collapse & draw air. I know that hose is original.

Any info would be a big help. Thanks!

Parts installed: Aftermarket Intake grate & Rideplate(I think R&D), Solas Impellor, Pump Seal kit & sealed with lots of 4200(done 3 times, ending with 4200), D-plate with sensor plug, Stepped sponsons, HoleShot kit, RIVA exhaust silencer delete(straight piped). I may have missed something.