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  1. #1
    Formerly Ultra250 TN Aquaholic6801's Avatar
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    250 Loosing Boost at WOT

    OK this has been a problem for a little while, even before all the problems I had last year.......

    If I am turning like low 7000's RPM I show 11.5-12 lbs of boost on my after market gauge, when I pin the throttle the rest of the way it drops @ 2 lbs of boost, I have had the engine out twice and intercooler in and out a few times so theres is no leaking hoses ,belts tight, so its nothing really obvious, unless I am over looking something.......

    The question is how do you test the Primary Relief Valve, the one that is vaccum activated (what Kawi calls it in the Manual), the one in line, I have blocked off the over boost (What everybody calls the BOV), on the intercooler a long time ago..... I have been through the Manual a couple of times and the is nothing that I have found that really says anything about it or how to test it........


  2. #2
    Take the time to smile sirbreaksalot's Avatar
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    Wink

    Quote Originally Posted by Ultra250 Tn View Post
    OK this has been a problem for a little while, even before all the problems I had last year.......

    If I am turning like low 7000's RPM I show 11.5-12 lbs of boost on my after market gauge, when I pin the throttle the rest of the way it drops @ 2 lbs of boost, I have had the engine out twice and intercooler in and out a few times so theres is no leaking hoses ,belts tight, so its nothing really obvious, unless I am over looking something.......

    The question is how do you test the Primary Relief Valve, the one that is vaccum activated (what Kawi calls it in the Manual), the one in line, I have blocked off the over boost (What everybody calls the BOV), on the intercooler a long time ago..... I have been through the Manual a couple of times and the is nothing that I have found that really says anything about it or how to test it........
    This may sound funny Harry but it will work

    I check and found my vavle to be leaking at WOT but running the OEM small vent hoses to outside the hull so I could see the end of the hose

    I then put a ballon over the end of the tube and taped it on,and cut the end off the ballon.it was a long sausage ballon if you must know

    Theory behind is as we know at engine VACUM loads its open/ bypassing

    So at WOT if the valve is bypassis you will see and hear the air bleeding past the vavle, as you can hear it in the engine bay

    Hope that makes some sence

    Warren

  3. #3
    GODOSIDIS's Avatar
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    Harry,
    try swaping the Primary Relief Valve with a friend.

  4. #4
    Dubz1's Avatar
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    We had a leaky bypass valve in our group. It's since been replaced.. BUT.. they aint cheap. Good start as Waz and chris suggested.

    Has anyone experimented with an aftermarket bypass valve? Like the one we are discussing?

  5. #5
    www.eastcoastpwc.net Scott's Avatar
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    Quote Originally Posted by Dubz1 View Post
    We had a leaky bypass valve in our group. It's since been replaced.. BUT.. they aint cheap. Good start as Waz and chris suggested.

    Has anyone experimented with an aftermarket bypass valve? Like the one we are discussing?
    I use an aftermarket one, turbosmart megasonic. A bit over kill. lol

    http://greenhulk.net/forums/showpost...5&postcount=94

  6. #6
    JET250's Avatar
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    but it sound big like you my fiend.

  7. #7
    Ultra250XRider's Avatar
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    Sounds like a problem I had last year. If you have the stock air intake, the intake horn can come free from the intake duct and press against the hull not allowing air in the the intake. You should be able to reach your hand there a feel it.


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  8. #8
    Beagleman62's Avatar
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    Quote Originally Posted by Ultra250XRider View Post
    Sounds like a problem I had last year. If you have the stock air intake, the intake horn can come free from the intake duct and press against the hull not allowing air in the the intake. You should be able to reach your hand there a feel it.


    I think harry has been running a homemade intake for a while

  9. #9
    SAL08HO's Avatar
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    It could also be a valve stuck open... You may want to take the head off and inspect your valves.

  10. #10
    NJRIVERRIDER's Avatar
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    Slipping belt at higher rpms?

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