Cavitation / Lack of hook up

[mac_man_luke]

Did a heap of riding on the weekend.

On the way back to the ramp on the last ride my ski started to cavitate out of the hole when given more than approx half throttle.

Basically didnt move, just bounced off the limiter.

Half throttle, no problems and it would still get up to full speed (or close enough)

I have checked:
Pump/prop - no issues, wear ring is still good and prop perfect.
Carbon seal- looks fine, 100hrs worth of wear and is being replaced. Will post some photos.
Drive shaft spines: both ends look very good - no obvious wear. Will post some photos.

Any ideas?

Thinking about putting it back together with new carbon seal and giving it ago - maybe what ever was in there fell out on while trailering it.

Was a single leaf in the pump when i got home but it was really small and fell out when i was flushing it so dont think that could have been it.

thanks
Luke

[shrabber]

Check for boost leaks. Loose clamps hoses sc etc. while your at it check sc and slip

[mac_man_luke]

dont think thats the problem because its hitting 8800 rpm but not going far. Seems more like a drive problem.

Had a boost leak last week and that was costing me RPM etc.

[imp0ster]

the pump is two piece. Take it apart and RTV it. if air gets in you boil water Might also want to check the rubber ass gasket that seals it to the hull

[shrabber]

Splines on drive shaft or sc slip

[mac_man_luke]

the pump is two piece. Take it apart and RTV it. if air gets in you boil water Might also want to check the rubber ass gasket that seals it to the hull

3 pieces actually with a wedge It is RTVed but has been a while.

Replaced the rear seal just last week.

Think im just going to have to test run it. Hopefully its not driveshaft splines because that is going to cost a heap (driveshaft+prop. maybe x shoe, ride plate etc)

[mac_man_luke]

Driveshaft pump end - some marking but no deformation.

Driveshaft pump end - some marking but no deformation.

Driveshaft PTO end

Old floating ring

carbon seal

[mac_man_luke]

Old vs new bellows

[monaroman76]

It all looks good Luke, My old drive shaft certainly doesn't look like that haha. Hopefully the new carbon seal and accordion boot sorts the issues out.