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  1. #1

    2004 800XLT High compression

    Servicing a 2004 800XLT today and the front cylinder is giving approx 160 psi
    Rear is 135-140 psi.

    I even tested with another very accurate tester to be sure.

    What is the most likely cause of the high compression, carbon build-up possibly.

    Ski has 95 hrs by the way

  2. #2
    something is off
    should be 120/120.
    There is nothing that will give you readings that high blockage wise...

    Make sure the other spark plug is in and the throttle is full open when doing your check

  3. #3
    I used 2 diff testers (one was calibrated last week to within 0.5 psi)

    I normally test with both plugs out, have tried in the past with 1 plug in and it makes very little diff.

    Something is causing the fron to be excessively high, Should hgave said this engine is standard, no mods.

  4. #4
    Join Date
    Aug 2005
    how many hours? have seen this in cars where the carbon build up will actually increase the static compression. the engine becomes more (loose) broken in, and everything turns much more easily. so there is actually more torque and horsepower than when it had 0 miles as opposed to 60k. but this is a whole nother beast here

  5. #5
    Pull the head and have a look see!!! Verify your power valves are still there and functioning correctly..................

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