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  1. #1

    ultra 250x full boost but only reaching 6400 rpms max! HELP

    Hi been trying to diagnose this problembut can't seem to figure it out I have tried changing out the pump and imPeller, switching out the intercooler, and its not working. the ski has full boost 10 pounds but will only get up to 6400 rpms max after holding the throttle for one minute it starts to drop down into the 5000 range. I have good compression in all cylinders and put new plugs In as well.


  2. #2
    Formerly Ultra250 TN Aquaholic6801's Avatar
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    Full boost is 11.4 lbs.....belt tension?

  3. #3
    nicjak's Avatar
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    Boost leak or intake horn, belt slip,

  4. #4
    I checked tension and trumpet and also changed fuel pump last night!! It got up to 7000 rpm and then while holding wot it started dropping down into 5000's.

  5. #5
    Formerly Ultra250 TN Aquaholic6801's Avatar
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    How did you check the tension?

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