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  1. 400ex question.

    Engine/EFI/Drivetrain
    i have a 400ex it has has 30 for compression. the cylinder wall has no scratches and looks good. its the stock piston in it. i noticed the first ring it collapsed or just stuck shut the other one isnt. should i just change the rings. or just oem piston and rings and change it or get it bored out...
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