Loss of thrust at full speed

[Bradc727]

Hello everyone, I am brand new to the forum hoping someone will ne able to help me out. I just bought a 96 sugar sands heat xrt jet boat. The boat starts and runs great at idle and low spees previous owner always took care of it took it to the shop every year to gwr annual "check ups". My issue is why I increase to 3/4 to WOT to cruise across the lake I lose thrust amd RPM go up, almost like it "slipped out of gear". When I slow back down to idle and then speed up again the problem goes away but comes back everytime I try to cruise across the lake. Check amd impeller is free of weeds, fish line and anything else. Impeller/wear ring spacing looks great. What could this be? Please help!!

 

[Seadeals]

It must be cavitation. Things may look okay but very small things can contribute to cavitation. I am not familiar with the pump used on sugar sands; but anything that isn't smooth in the intake or any anomaly on the impeller versus spec could cause it.

 

[Bradc727]

Thank you! I will take a look tomorrow and see how everything looks. Some other advice i got was to check the ride playe and screws for flushness. Sounds very similar to yiur suggestion.

 

[Bilmon]

Agree that it's cavitation Check that the seal around the pump/rideplate is flush and intact, torn or missing sections will create turbulence which can cause cavitation

 

[Steven smith]

I am having the same problem please help

 

[Bradc727]

I got underneath the boat while it was on the trailer and I found that the, ride plate?? was hanging lower then it should dontona bad gasket so it was causing and interuption in water flownat high speeds. I was able to go to local motor sports store and the same sealant they ise for jetski ride plates and I am also having a scooped intake grate fabricated. I would check underneath the boat and look for anything that could inturpt the flow into the intake great or that could cause a large amount of air bubbles to form and be pulled into impeller. I am new to jet boats but that is what I am going to try. New impeller is not complete yet.