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  1. #1
    mac_man_luke's Avatar
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    Compression test / engine health

    Hello all

    I finally ran a compression test and i wish i hadn't ...

    Ski warmed up on the hose (so no where near operating temperature) and all plugs removed.

    1 - 125-135psi
    2 - 125-135psi
    3 - 100-105psi

    Put a bit of oil in the cylinder and it brought it up to 120-125psi so I'm thinking rings are on there way out

    Im thinking 3 is the leanest cylinder if i remember correctly?

    Still runs fine although a bit down on top end from my best numbers.

    Am i going to do much more damage if i keep riding it? hopefully get a full rebuild over winter if i can justify the cost.

    Will re-run the test after a ride at full temp - guessing that will give better numbers overall but 3 will still be low no doubt.

    No doubt to do with the less than perfect tune as its only got 120hrs on it.


  2. #2
    Pete1027's Avatar
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    I see your on my side of the world mate...

    I cant see why you would do any more damage if you kept riding it. It might burn a bit of oil and maybe blow a little smoke when it gets really bad. Should be fine for the rest of this very average summer we are having.

    What tune is in it if i could ask?

  3. #3
    mac_man_luke's Avatar
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    Its a vtech tune but its never been fully dialled in due to a strange ecu in my ski meaning I'm one only a few running it (and have yet to get them to unlock the custom tuning bits properly) Generally been run rich rather than lean though.

  4. #4
    Turbonut's Avatar
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    I was running my RXP for a while with stuffed rings (after a couple of overheats). Got a lot of blow by and was filling the catch can pretty quickly but that's about it.
    I'd say run the rest of summer (keeping an eye on things) and build the forged race motor over winter.

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  6. #5
    monaroman76's Avatar
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    Quote Originally Posted by Turbonut View Post
    I was running my RXP for a while with stuffed rings (after a couple of overheats). Got a lot of blow by and was filling the catch can pretty quickly but that's about it.
    I'd say run the rest of summer (keeping an eye on things) and build the forged race motor over winter.
    I agree with this.
    You got a leak down tester Luke? That'll give you a better idea of how well the rings are sealing..

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