Honda do not give bore size specifications for the MC21, only bore/piston matching data.
I you have a "B" cylinder, you want a "no mark" piston.
If you are having cylinders replated, then it doesn't really matter what piston you have - just send it along to the plater with the barrel and tell them the clearance you want!
It is adviseable to stick to Honda's table though, to make it easy for future reference.
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Andy.
NSR-WORLD.COM
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