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Thread: Speed Drop?

  1. #1

    Speed Drop?

    So a couple weekends ago I had my 2001 GTX around 53-55ish mphout on the lake which considering its age and hp isn't hard to argue with but i've run into a problem. For some reason, yesterday when i took it out the highest i was pulling was 47 mph with the throttle pinned and the water like glass. I'm not too handy with Sea Doo's and not too sure why the sudden drop of power. Does anyone have any suggestions or help? Any info would really be appreciated.


  2. #2
    diamondwatercraft's Avatar
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    Can you think of anything that happened like sucked up weeds or ran over the ski rope?

  3. #3
    I ran over some fishing string earlier on this summer but it was light, most of it came out, and it still ran near 55 after the incident. After finding that is wasn't pulling as much I got under, which is a lousy job, and fished barely any seaweed out. So as far as I can tell nothing is stuck in the impeller. I got some seafoam to run through the lines which and we'll se if that makes a difference. Id like to try and keep her in best performance haha. Thanks man

  4. #4
    She went down to 43 today on glass and really trying. Anyone else have any ideas about why this could be happening?

  5. #5
    AndinoWatercraft's Avatar
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    Start with a fresh set of sparks. Remove the seat and look near the sparks for two plastic black caps (rave valves) carefully remove the caps (they have a spring inside and you don't want to loose it) start the ski and rev it up. Look if the inner part of the valve comes up when reving . If this is not happening could be a cause of your lack of speed. Those valves are controled by a selenoid that with age it can short. Also wouldn't hurt and is easy to remove the full valve and clean it . If it has to much carbon deposits it will not fully open causing the exhaust port no to open fully. Sorry for the english.

    Hope this helps.

  6. #6
    Ive heard that if I clean them ive got to put a new gasket in. Instead of keeping the old one. Is that true?

  7. #7

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    They use oring seals. No gasket issues. Remove the two allen bolts and try to lift out. If they dont budge, you will need to work back and forth till they lift out. This could be one of your problems. Your ski regardless of age and hours should easily run 58 mph. Should also see well over 6750- 6800 is tuned properly. With some simple improvements, it will break 60 without any surprises. If the RAVES are all oily, then you found one of the problems. I am thinking there are some other underlying issues too. Keep posting what you find. I am assuming this ski is a carb'ed GTX with the 951 motor. If not we need to approach some things differently.

  8. #8
    Kenway's Avatar
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    Your RAVE valves have a rubber gasket where the valve mounts to the engine, part number 290 931 670. It also has a rubber o-ring, part number 290 931 765 on the shaft of the exhaust valve. If they are damaged or crushed, for their cost, I would just replace them.

  9. #9
    Wrench's Avatar
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    Quote Originally Posted by AndinoWatercraft View Post
    Start with a fresh set of sparks. Remove the seat and look near the sparks for two plastic black caps (rave valves) carefully remove the caps (they have a spring inside and you don't want to loose it) start the ski and rev it up. Look if the inner part of the valve comes up when reving . If this is not happening could be a cause of your lack of speed. Those valves are controled by a selenoid that with age it can short. Also wouldn't hurt and is easy to remove the full valve and clean it . If it has to much carbon deposits it will not fully open causing the exhaust port no to open fully. Sorry for the english.

    Hope this helps.
    If you take the spring out the raves will come up. The point of the spring is to keep them pushed down until crank pressure overcomes the spring force and pushes the raves up.

    Just take the caps off and see if the valves move in and out easily by hand. If they feel like they stick a bit take them out and clean them. Super simple process to do.

  10. #10
    AndinoWatercraft's Avatar
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    Thumbs up

    Quote Originally Posted by Wrench View Post
    If you take the spring out the raves will come up. The point of the spring is to keep them pushed down until crank pressure overcomes the spring force and pushes the raves up.

    Just take the caps off and see if the valves move in and out easily by hand. If they feel like they stick a bit take them out and clean them. Super simple process to do.
    You are right. Thanks for the correction.

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