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  1. #1
    AReiter's Avatar
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    Chasing RPM loss

    Have an '04 rxp and I had the supercharger rebuilt over the winter and added a Les Cooke fogging system. At the end of last year I recall turning about 7800-7900 rmps and the top speed on the speedo was 71. I take it out this year and the best I can get is 7450 with a top speed on the speedo of 68. Tried a new wear ring.. same thing. Plugs are new this year and running 91 octane fuel. Another symptom thats occuring this year is after jumping a wake the ski will occasionally bog down and act like its going to die but then comes right out of it and runs fine.

    What does it sound like to you guys? I don't know if its my charger is slipping, if a have a boost leak, or if possibly my injectors need to be cleaned

    Let me know what you think!


  2. #2

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    I believe you rev limit is 8200 on that ski. Anyhow can you check the slippage on the sc, it should be fine but its fairly simple to check and doesnt take to much time, why not check it? And the bogging down part i am lost on.

  3. #3
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    Quote Originally Posted by AReiter View Post
    Have an '04 rxp and I had the supercharger rebuilt over the winter and added a Les Cooke fogging system. At the end of last year I recall turning about 7800-7900 rmps and the top speed on the speedo was 71. I take it out this year and the best I can get is 7450 with a top speed on the speedo of 68. Tried a new wear ring.. same thing. Plugs are new this year and running 91 octane fuel. Another symptom thats occuring this year is after jumping a wake the ski will occasionally bog down and act like its going to die but then comes right out of it and runs fine.

    What does it sound like to you guys? I don't know if its my charger is slipping, if a have a boost leak, or if possibly my injectors need to be cleaned

    Let me know what you think!


    Who rebuilt the SC?
    Who reinstalled the SC?
    What is your oil level?
    How fresh is the gas?
    Where was the ski stored?

    04's limit is 8150, 8100 is what you want...
    Speedo's don't show higher than 70...

  4. #4
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    Quote Originally Posted by Danny View Post
    Who rebuilt the SC?
    Who reinstalled the SC?
    What is your oil level?
    How fresh is the gas?
    Where was the ski stored?

    04's limit is 8150, 8100 is what you want...
    Speedo's don't show higher than 70...
    My local dealer rebuilt the SC
    I reinstalled the charger myself
    I thought of the oil also and cheked it... right in the middle of the bends..
    The gas was fresh from the pump
    Ski was stored in a cold storage shed..

  5. #5
    Everthing louder than everything else! sHALlow's Avatar
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    knock sensor update?

  6. #6
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    Quote Originally Posted by sHALlow View Post
    knock sensor update?
    I believe so.. Just had the ski hooked up to BUDS last week and ran it over the weekend without getting a fault code. One code I do still have though is GPS out of range, that still needs to be cleared..

  7. #7
    Everthing louder than everything else! sHALlow's Avatar
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    http://www.greenhulk.net/forums/showthread.php?t=105724

    read the second post, even tho hooked up the buds, if no pigtail you will still be upshitcreek. otherwise i would say the check your pump area, veins, pump seal, intake grate, etc. any cavitation or water in the hull? maybe carbon seal.

  8. #8
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    Quote Originally Posted by AReiter View Post
    I believe so.. Just had the ski hooked up to BUDS last week and ran it over the weekend without getting a fault code. One code I do still have though is GPS out of range, that still needs to be cleared..

    GPS out of range? They don't have GPS's in 2004's...

    If you reinstalled it, do a quick test for us....Take off the SC inlet tube that feeds air to it....Using 2 fingers on the leading top edges, try turning the SC in the direction it would normally go...Since its stock, it should be tough, go about 1/16th of a turn, and then stop....If it goes any farther than 1/8th then its got too much slip...

    Also, when was the oil changed? By who? What was used to replace it...

    If it was the knock sensor, 7300 would be your limit...

  9. #9
    Everthing louder than everything else! sHALlow's Avatar
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    Quote Originally Posted by Danny View Post
    GPS out of range? They don't have GPS's in 2004's...

    If you reinstalled it, do a quick test for us....Take off the SC inlet tube that feeds air to it....Using 2 fingers on the leading top edges, try turning the SC in the direction it would normally go...Since its stock, it should be tough, go about 1/16th of a turn, and then stop....If it goes any farther than 1/8th then its got too much slip...

    Also, when was the oil changed? By who? What was used to replace it...

    If it was the knock sensor, 7300 would be your limit...
    thought it was 7600???, but Danny knows his stuff for sure. on the lines of SC slip, makes me think boost leak somewhere as well perhapshmere. check pipe couplings at SC, TB, and IC.

  10. #10
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    Everyones advice here is good.

    I would just like to add, that the hesitation you feel after wave jumping is most likely your TOPS engaging. This is no big deal.

    Or else, it could be water ingestion if you are getting a lot of water coming over the front. If it is the case of water ingestion, you could have damaged your plugs. I would change them again just to be sure. 7400 was about my limit when I had water damaged plugs.

    Good luck.

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