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  1. #1

    Gp800r revving flat out help!?

    am posting on behalf of a friend.

    He purchased a GP800 (2003) bog standard.

    When the ski was purchased from the a long way away....

    The ski turned up, he started the Ski and it ticked over he revved it (blipped the throttle) and it carried on revving flat out, pulled the plug caps off carried on running on heat and fuel and hit the cut off....

    He is a carmechanic, decided since the happened he scored the bores, rebuild the motor, new crank seals etc..

    Its all back together, started it up, ticks over fine, give it some revs the thing starts to run flat out, but knowing its done this before killed the engine before damage was done. Disconnected the throttle leaver, started the ski and revved by hand closing the butterfly.... same again... revved it nuts off...


    It had a manual choke and the choke is closed.... the carbs havent been stripped yet...


    He has checked the manifold for leaks gaps etc nothing... starting to run out of ideas...

    Sounds like carbs to me as its not the engine, or eleactrics....


    Does any one have ideas? do you think the needle is not closing ?

    Any ideas? He hasnt stripped the carbs yet...

    The previous owner sdaid it ran fine but he would say that?

    Thanks

    Nathan


  2. #2
    IrishGpr05's Avatar
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    Chances are it's the carbs and they need to be rebuilt.

    Did he pressure test the motor after building it? This is not the same as a compression test.

    -Jon

  3. #3
    Moderator OsideBill's Avatar
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    Lean runaway common in two strokes that are (a) starved for gas or (b) have an air leak.

    best way to stop it, is to open throttle wide open.

    I tell people who have installed newly rebuilt carbs to remove the return line, pull the plug wires, run the return line into a container, then crank the ski until fuel is flowing from the return line this insures that fuel is now present at all carbs. The same may be the case for a ski that has set for a long period of time. Thw carbs also may need rebuilding.

  4. #4
    Thanks for the heads up guys, I will get him to rebuild the carbs.

    Does anyone know the Stock settings for the adjustments of the carbs? IE 1 1/4 low 1 1/1/2 high?

    Thanks
    Nathan

  5. #5
    He didnt pressure test the engine, he did a compression test... how did you pressure test the engine?

    I did the same before it was rebuilt, and still doing the same..


    Thanks
    Nathan

  6. #6
    Moderator OsideBill's Avatar
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    Quote Originally Posted by dubvdub View Post
    He didnt pressure test the engine, he did a compression test... how did you pressure test the engine?

    I did the same before it was rebuilt, and still doing the same..


    Thanks
    Nathan
    Do a search on pressure testing lots of threads containing this info.

  7. #7
    WE DONT DIAL 911 RDH's Avatar
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    i answered you on another forum, days ago.... glad you found this site, the answers will come much quicker

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