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  1. #1
    Rendog's Avatar
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    Angry scary compression readings

    Well, I notice my ski over the last few days seemed to be dumping a bit more into the catch can. And also noticed a light white smoke that I haven't seen before! Ski seemed to be lacking that top end punch from a week ago also! Plugs were a bit wet also 170 hours on motor

    Compression findings: cold engine, plugs in other cylinders, battery fully charged, Throttle held WOT!

    1)152

    2)86

    3)102

    Checked 3 different times with two separate gauges!

    Ran second test later with fogging oil sprayed into cylinders

    1)159

    2)100

    3)106

    Looks as if I will be pulling a head soon and possibly more!
    Last edited by Rendog; 06-06-2010 at 09:10 PM. Reason: more info


  2. #2
    Nothin' better than Doo'in it! BigDaddyRXP's Avatar
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  3. #3
    Rendog's Avatar
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    170 hours

  4. #4
    Nothin' better than Doo'in it! BigDaddyRXP's Avatar
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    You need to check your compression with a warm motor!

  5. #5
    Rendog's Avatar
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    alright, ill do it tomorrow after work and post readings

  6. #6
    Vern's Avatar
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    What ski??? I have gotten anywhere from 120 - 150 psi compression on my RXP, depending on where cam timing is, whether there are spark plugs in other cylinders, etc, on a cold engine with a freshly charged battery. So hot or cold makes little difference, possibly 5 lbs difference on average ... so unfortunately your readings do sound scary. Pull the valve cover and take a close look at your valves for a start, and verify cam timing marks, etc.

  7. #7
    cold engine
    , plugs in other cylinders,
    battery fully charged, Throttle held WOT!
    I know it makes a diff in 2 stroke engines but does it affect these 4 tec motors not having all other plugs in??

  8. #8
    Vern's Avatar
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    It does ... I got 145 in all 3 with no spark plugs in, throttle held WOT. Put in 2 spark plugs, got 150 in each cylinder. Fresh battery, cold engine.

  9. #9
    Rendog's Avatar
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    2005 RXP I run the ski year round and know its just a matter of time before I need to change the valves anyway

  10. #10
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    Really need to have the other 2 plugs in when doing compression readings. Charger on the battery also helps with consistancy.

    Leakdown always tells the real story.

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