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  1. #1

    1200 GP Erratic compression

    Gents,

    I have a 2002 Gp 1200 with 72 hrs. I just got it but it has been sitting for a couple of years.

    When I first took compression numbers they were 120,120,120. I put fresh gas in it and when it fired I shut it off. The compression numbers were then 120,60,120.
    I turned it over with the plugs out and got the center compression to 120. I ran it for a couple of seconds and checked it again, it was 120. I did this several times and did get the 60 number 1 other time.
    Any Ideas?
    Could this be a clogged reed valve or something?
    Thanks


  2. #2
    THE PLATE MAN JIM'S PERFORMANCE's Avatar
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    Quote Originally Posted by Hamme001 View Post
    Gents,

    I have a 2002 Gp 1200 with 72 hrs. I just got it but it has been sitting for a couple of years.

    When I first took compression numbers they were 120,120,120. I put fresh gas in it and when it fired I shut it off. The compression numbers were then 120,60,120.
    I turned it over with the plugs out and got the center compression to 120. I ran it for a couple of seconds and checked it again, it was 120. I did this several times and did get the 60 number 1 other time.
    Any Ideas?
    Could this be a clogged reed valve or something?
    Thanks
    a sticky ring can cause that, Being it has been sitting for a couple years. Add about 3 ounces of oil in the cylinder put it on the hose fire it up and let it run for a while.

  3. #3

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    make sure you are using a good comp gauge, cheap gauges do not give consistant readings, snapon & mac tool have good ones

  4. #4
    DAGO RACING CREW 97GPSLEEPER's Avatar
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    Make sure the oring on the gauge is sealing like it should. If you tighten too much the o-ring will get deformed and if it's not tight enough it will not seal.

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