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  1. #1

    fx svho low top speed

    fx svho 37 hrs stock,speed 67 mph gps 7600rpm 99 octane fuel quarter of a tank 85 kg rider at sea level 16 deg water temp 20 deg air.
    no fault codes seems to run fine just low top speed. fresh plugs oil and filter.
    changed prop for a skat trak repitched set back and worx grate and stuffer kit 66.4 mph at 7550 rpm.
    all clamps tight on exhaust and charger/ic.no leaks
    the speeds seem low compared to others ,is there anything else I should look for that would cause low top speed ?


  2. #2
    zone5's Avatar
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    That does seem a bit low, at the same rpm 3000' AMSL I am getting 110 km/hr GPS... Fresh water too...

    What has the prop been pitched to? It seems like the engine is delivering, so either not enough velocity out of the pump or something in the grate/plate/hull causing drag...

    I actually only run 95 RON (would that be 91 AKI to you guys?) as I have subjectively had a feeling that the really high octane fuels don't deliver the same calorific output or may contain other things which limit power. Mmm, may be something there, because I do get that same rpm as you at an altitude which would create a 9% power reduction from sea level...

  3. #3
    I had the same problem, a gasket come out of the intercooler and eventually lodged its self in the trottle body.

  4. #4
    Thanks for the replays. I forgot to add is it normal for this ski to drop 500 rpm cornering?

  5. #5
    shrabber's Avatar
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    Get You a scom You will be happy Changing anything in between is ... Pointless

  6. #6
    Quote Originally Posted by shrabber View Post
    Get You a scom You will be happy Changing anything in between is ... Pointless
    I can only run this boat stock apart from prop and grate for racing.

  7. #7
    shrabber's Avatar
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    Don't expect much then matter of fact changing the prop will make You slower..

    Grate will help with hook up...

  8. #8
    I really thought this ski would be faster than 67mph stock I'm just chasing speed I thought it would have had

  9. #9
    Quote Originally Posted by zone5 View Post
    That does seem a bit low, at the same rpm 3000' AMSL I am getting 110 km/hr GPS... Fresh water too...

    What has the prop been pitched to? It seems like the engine is delivering, so either not enough velocity out of the pump or something in the grate/plate/hull causing drag...

    I actually only run 95 RON (would that be 91 AKI to you guys?) as I have subjectively had a feeling that the really high octane fuels don't deliver the same calorific output or may contain other things which limit power. Mmm, may be something there, because I do get that same rpm as you at an altitude which would create a 9% power reduction from sea level...
    In uk thats 99 Ron (always pulls a little harder I find)

  10. #10

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    Quote Originally Posted by Richard John Rowe View Post
    Thanks for the replays. I forgot to add is it normal for this ski to drop 500 rpm cornering?
    Yes thats normal for these new FX hulls. They really eat up the RPM's through the turns, once you straighten it out it will feel like a sling shot in acceleration with your speed and RPM's.

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