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  1. #1
    It got WIFI and touchscreen ! PWCGUY's Avatar
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    Question Low Compression Cyclinder #3 @ 22 Hrs

    After reading a bunch of threads regarding cam timing I decided to do a compression check as a first indication. The results were #1 - 140 psig, #2 - 140 psig, #3 - 128 psig. This is an 08 RXP-X bought new this year and now has 22 Hrs.

    So cam timing is probably o.k. but now concerned about cylinder #3. This is the first time I have done a compression check and the performance of the motor is o.k. 8120 rpm @ 74 mph with 1/4 tank gas. Is it possible that the motor is not fully broken in ? I have riden it hard for 12 - 14 hrs now and if this was a breakin issue I would expect cylinders #1 & 2 to also be low. Is it most likely the rings, valves ? Should I pull the head ?

    I'm running a 4 inch intake, worx grate, ros neno TB, intake manifold FA removed, torque plate and just installed JD1 open loop ( 4hrs ), RE block offs, RIVA ride plate, everything else stock.

    Any help would be appreciated.


  2. #2

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    How did you check the the compression? Did you hold the throttle wide open? did you do it more than once one each cylinder?

  3. #3
    It got WIFI and touchscreen ! PWCGUY's Avatar
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    Yes throttle was held wide open and motor was warm. I repeated the compression test over the coarse of several days and got consistent results.

    The first test I did several days ago was with a cold motor and in that case the compression numbers were much closer togather. When I warmed the motor up and repeated the test cyclinder # 1 & 2 improved to 140 psig but cylinder # 3 stayed about the same at 128 psig ( warm & cold ).

  4. #4
    King_Of_Fun's Avatar
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    If you do the test again, you might try squirting a little engine oil in #3. If the compression comes up, the rings a leaking a little. But, it's still less than a 10% difference than #1 and #2. It would be interesting to know when BRP would OK a repair. My guess would be that the cylinder would not have enough compression to fire before they would pay the bill... Ron

  5. #5
    use2vtec's Avatar
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    Quote Originally Posted by King_Of_Fun View Post
    If you do the test again, you might try squirting a little engine oil in #3. If the compression comes up, the rings a leaking a little. But, it's still less than a 10% difference than #1 and #2. It would be interesting to know when BRP would OK a repair. My guess would be that the cylinder would not have enough compression to fire before they would pay the bill... Ron
    +1, put a few drops of oil in that cylinder. If the comp comes up its a ring issue if no change its more than likely in the head. Or if you have the tools you can do a leakdown test and try to narrow it down that way.

  6. #6
    speedskixp's Avatar
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    Quote Originally Posted by King_Of_Fun View Post
    If you do the test again, you might try squirting a little engine oil in #3. If the compression comes up, the rings a leaking a little. But, it's still less than a 10% difference than #1 and #2. It would be interesting to know when BRP would OK a repair. My guess would be that the cylinder would not have enough compression to fire before they would pay the bill... Ron
    BRP says 45% leak down is acceptable.

  7. #7
    It got WIFI and touchscreen ! PWCGUY's Avatar
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    Squirted in some WD40 and the compression in #3 came up to 142 psig. I still don't know if it is the rings or valves. The WD40 could have help either problem or am I missing something ?

  8. #8
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    Quote Originally Posted by PWCGUY View Post
    Squirted in some WD40 and the compression in #3 came up to 142 psig. I still don't know if it is the rings or valves. The WD40 could have help either problem or am I missing something ?

    If the compression went up when squirted WD40 then you pistons rings are worn.

  9. #9

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    Re: Low Compression Cyclinder #3 @ 22 Hrs

    Do a leak down test. This will be more informing. You might be able to rent a good quality leak down tool. You'll need a air compressor a well.

    My px has a little bit of leak down in cylinder 3.... I guess there was a problem with the X rings from the factory.


    Sent from my iPhone using Tapatalk

  10. #10
    GOT BOOST? Dockside's Avatar
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    Quote Originally Posted by pdxrealtor View Post
    Do a leak down test. This will be more informing. You might be able to rent a good quality leak down tool. You'll need a air compressor a well.

    My px has a little bit of leak down in cylinder 3.... I guess there was a problem with the X rings from the factory.


    Sent from my iPhone using Tapatalk
    it it just on the X ski or have there been ring problems on the 08 215 aswell?

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