1996 challenger 787 wont pull a tube

[gasman_1_2]

Last year we had the boat out to tube and we got ready to go and it wouldnt plane out and go i had it wot and as fast as it would go was 10 to 15mph the rave valves were completly replaced and cylinders cleaned and compression on both were 120 psi it has a stak trak impeller on it would that cause it to loose power versus the factory stock impeller and when not tring to pull anything we get on plane and it goes about 40 to 45 with 2 people in it and the rpms wot is about 7100 to 7300 if anyone can give any ideas it would be much apperciated

 

[sporsterjoel]

Id check your wear ring. In my boat i had a couple peopl in it and it was fine but a couldnt wakeboard behind it and it was a wear ring. Its an easy thing to check and rule out. also do you have gray fuel lines? if so they need to be changed.

 

[Gunsrunner]

I'm fairly sure i've read that this model has a neopreane seal between the jet pump and hull and that if this is worn or damaged it can cause air to be sucked into the jet causing cavitation.
Does it sound like it's reving and not getting anywhere?
Or as above it could be wear ring:agree:

 

[kustomkarl]

It needs a wear ring....

Karl