96 GTX cavitating when towing

[Paul 1996]

Ive got a 96 GTX, when getting a skier up it cavitated with the revs jumping to max. I had to back off for the prop to hook up again. The shaft isnt bent I checked the clearance to the wear ring, thats ok and the prop is nice and sharp. It runs the carbon pto water seal, the stainless face has a few pitting marks but should give a sealing face, is this where the air is getting in?

how do you preload the compression on the convoluted boot to ensure there is corect pressure on the seal without to much pressure. Can I convert to a proper bearing with lip seals from another model?

 

[PWCdoc]

Your cause/issue in in the pump. What is the clearance between the impeller and wear ring?

 

[Paul 1996]

It measures in at 15 - 20 thou, service manual allows for up to 40 thou. The plastic wear ring has some marks but nothing too bad.One week it was ok towing and inline Rocket tow toy with one big adult on it and two on the ski, the next week towing a conventional round biscuit or a water skier, this problem appeared.

I took the jet unit out a month ago to check everything and when I put everything back, I made sure to put plenty of compression in the convoluted boot. When I stripped everything down on the weekend, I thought the boot has slipped, less pressure holding the carbon and stainless faces togeather.