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  1. #1

    Gp1200 cylinder question

    New to me ski with 10-15 hours on the motor.
    Motor was rebuilt by the PO
    Checked compression, front cylinder had 100-105, the other 2 had 125
    Added oil to the front cylinder, no change.
    Took the ski for a short GPS speed test, retested the compression, the 2 still at 125, front now at 70.

    I took off the head thinking gasket leak. I found a slight piles film beteem the cylinder top and the gasket on the low cylinder, approximately 50% of the circumference. So I'm thinking bad gasket seal.

    Well in better am light I see this just above the exhaust port. Please say this is OK and I don't have to remove the cylinder. Click image for larger version. 

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  2. #2
    Myself's Avatar
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    That appears to be a gouge and maybe some fresh wear on the power valve. Possibly a ring spun, lost a locating pin, power valve keeper about to fall off, you need to pull it and find out what's going on.

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