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  1. #1
    Moderator Snoman's Avatar
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    1998 GP 800 porposing

    I was woundering if you yamaha guys could help me out..

    I have a friend of mine who has a 1998 GP 800.He has been recently noticing it porposing at high speeds..I understand the porposing on a RXP but what causes and fixes are avaliable for this old of yamaha ski???Thanks guys for all your help..

    Scott


  2. #2
    krispaintballz's Avatar
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    what ride plate and sponsons is your friend using?

  3. #3
    Moderator Snoman's Avatar
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    Quote Originally Posted by krispaintballz View Post
    what ride plate and sponsons is your friend using?

    Everything is OEM from what he was telling me..

  4. #4
    krispaintballz's Avatar
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    i would shim the ride plate in front down a bit and try to get some after market sponsons. I really think its the sponsons. Does he have them both set at the same height? I reallly hated them. they were junk.

  5. #5
    Moderator Snoman's Avatar
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    Yes they are both at the same height..He had them all the way up and tried them all the way down..This is what i dont get..He said when he had them all the way up the ski would turn on a dime..When he put them all the way down it would feel loose and spin real easy when taking a turn???? To me thats completely opposite of what i know about sponsons..What sponsons do you guys recommend??Riva,R&D??

    Thanks

  6. #6
    quadzilla's Avatar
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    ???

    Hey there Snoman..

    Like Kris said,

    The stock sponsons are J-U-N-K..!!!

    Get some aftermarket one's on there..

    Anything is better than the YAS crapola..!!!

    Fucck even a couple of lumps of wood cut to shape would be better..

    Through the up = handle's better, down = spins out, don't make sense..??

    Ebay or post a WTB in the classified's is your first step..

    Some are easy to attach to the ski,(Riva) some are pretty damn awkward (beach house.. (mine.!))

    Good luck with the search..

    Gerry

    PS.. the GP's porpoise like a S,O,a B, at the best of times anyway..

  7. #7
    Moderator Snoman's Avatar
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    Quote Originally Posted by quadzilla View Post
    Hey there Snoman..

    Like Kris said,

    The stock sponsons are J-U-N-K..!!!

    Get some aftermarket one's on there..

    Anything is better than the YAS crapola..!!!

    Fucck even a couple of lumps of wood cut to shape would be better..

    Through the up = handle's better, down = spins out, don't make sense..??

    Ya thats what i said..

    Ebay or post a WTB in the classified's is your first step..

    Some are easy to attach to the ski,(Riva) some are pretty damn awkward (beach house.. (mine.!))

    Good luck with the search..

    Gerry

    PS.. the GP's porpoise like a S,O,a B, at the best of times anyway..
    Thanks Gerry and Kris!!!!! I will tell him to get rid of the OEMs and order some Aftermarkets...Im sure he will appreciate it..

    Scott

  8. #8

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    spent over 500 bucks and am still tweaking the poropouse off of my machine. the beach house suck balls to put on, but the adjustments well make up for it.
    if you want to get rid of it, r&d trim tabs, plate and grate, and definately sponsons. it worked for me!!!

  9. #9
    2008 RXP-X
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    Girlfriend had the same ski with the same problem.
    Solution- R&D ride plate, intake grate. Then shim with 2 stainless washers on each side the 2 rear mounting bolts of the ride plate. As mentioned either replace or adjust the stock sponsons almost all the way down(what I did).
    Problem Solved.

  10. #10
    cfgp927's Avatar
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    R&D rideplate or Riva pro plate....stay away from the "groovy" plate it sucks. R&D intake grate or Pro-tec intake grate. Aftermarket sponsons (anyone's) just get rid of the stock ones unless you modify them to go further up or down. You might have to shim the ride plate with a couple of washers. Unless it's an early '98 hull you probably don't need the trim tabs. I never ran them on my '99.
    Mike

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