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  1. #1

    Opinions on pump damage

    Hello everyone,

    Over the weekend my pump bearings went, so I spent today pulling the pump off of my ski (1996 SLT700). I removed the cone on the stator to find the bearings full of water. That's the easy fix. The bad part is that the impeller was rattling around in the wear ring when the bearings failed. Attached are some pictures of the damage on the wear ring and impeller. There are scratches/scuffs in the wear ring but nothing that my fingernail can catch on. Also, there is a burr on the impeller vanes where it was rubbing the wear ring. The last pic is of a chunk thats missing off of my stator. Its been that way since I bought the ski but figured I'd ask opinions on how that would affect the ski's performance. Thanks for any input!!

    --Justin

    P.S.--Sorry for the large pics, just wanted to have enough detail.








  2. #2
    She likes the bike. But the ski gets her wet!!!! xlint89's Avatar
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    What's your clearance???? 20 thou is the service limt with 4 or 5 thou being recommended.

  3. #3
    well, I tried to measure it but the impeller flops around. So, if I move the impeller to one side, the 0.020 inch feeler gauge fits through, but if I move it to the center the best I can, it doesn't fit. So I'm not sure. I figure I'll need to replace the bearings before being able to tell if the clearance is good or not. Am I right?

    --Justin
    Edit:

    I just went back out and put the wear ring back on the stator and shoved the impeller over to one side and measured the clearance on the opposite side. My 0.040 in feeler gauge fit in the gap, which probably means, when centered there would be a clearance of at least 0.020 inch which means its shot. Whatabout the stator? What will affect will that chunk missing have? Thanks.

  4. #4
    She likes the bike. But the ski gets her wet!!!! xlint89's Avatar
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    If the impeller "flops" around, you DEFINATELY need new bearings.

    You're prob going to need a new impeller, or have that one refurbished.

    As for the chunk missing, it's not good, but it's not going to kill your performance too much either. Some, but not alot.

  5. #5
    Thanks for the input. What are some good brands for aftermarket impellers, or are there some specific ones to stay away from? I had my eye on a solas concord or IJK; either of those any good?

  6. #6
    She likes the bike. But the ski gets her wet!!!! xlint89's Avatar
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    Depends on what you're looking to gain. Top speed or acceleration.

    You can have the stock one refurbished for less than $100 by places like Impros or even Skat trak

  7. #7
    probably looking to gain some acceleration. Since I've owned it, it bogs for a few seconds before getting up on plane. Thats probably a combination of the chunk missing on the stator and a worn pump? I don't know, I'm pretty new to this stuff, but looking to learn.

    --Justin

  8. #8
    Click avatar for tech links/info, donation request K447's Avatar
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    Bogging before planing...

    Does the engine rev up right away but it feels like the impeller is just 'spinning' before gaining traction?

    Or does the engine itself take a moment to built RPM before accelerating?

  9. #9
    Sorry, confusion of terms; the engine does rev, but it feels like the engine is spinning a lot for the ski not moving. Would that be the pump cavitating?

  10. #10
    Click avatar for tech links/info, donation request K447's Avatar
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    Arrow What causes jet pump Ventilation and jet pump Cavitation?

    Quote Originally Posted by WhiteRover View Post
    Sorry, confusion of terms; the engine does rev, but it feels like the engine is spinning a lot for the ski not moving.

    Would that be the pump cavitating?
    Cavitation or ventilation, or possibly both.

    Ventilation means there is poor sealing between the jet pump and the hull. The jet pump is sucking air in along with the water, and the resulting air bubbles reduce thrust.

    Cavitation is usually caused by damage or wear in the jet pump. Damaged impeller blades (bent, dinged up, or worn) cause turbulence in the water that creates vacuum bubbles. These vacuum bubbles rapidly collapse as the water flows through the pump and cause reduced pump thrust, and often erode metal surfaces with the pump.

    As the hull picks up speed the water pressure within the jet pump rises, ventilation ceases and thrust increases.

    First check your jet pump for signs of damage and wear.

    If you still have the 'spinning engine without much thrust' problem and the jet pump is in good shape, then you probably have ventilation happening.

    The fix is to remove the jet pump and ride plate and re-seal them to the hull, making sure that there is no place for air to leak into the pump. Even a pin hole air leak can reduce pump thrust.

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