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    '88 JS550 cylinder bore/piston size

    I recently picked up a 550 that the motor was out of so i am rebuilding it now. i need to order my top end/piston kit now but i am wondering on piston size. i measured the bore and right now it is at 75.4 mm and i can tell its been taken apart once before and rebuilt. the pistons i pulled out have a 50 on the top of them, not a.50 so i wasnt sure if they are in fact .5 oversize. i was wondering if anybody knew the bore size to piston size and could tell me what i should put in. im looking at kits from WSM and they have one that is 75.25 mm, so could i get that kit and drop them in with a 75.4mm bore? or is the 75.25 size referring to the bore and not the actual size of the piston?
    Last edited by calvin650; 05-10-2014 at 08:36 PM.

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