Motorcycle Cylinder Engine Seal Bore 66mm 67mm Fit For Honda CRM250 oversize 100 motorcycle piston ring cylinder gasket kits set bore size 66mm +100 67mm direct cylinder assembly , oversize cylinder structure , no extra or adjustment needed stable compression sealing , maintains steady engine power output , reduces internal pressure loss hardened piston rings , dense gaskets , for flat uniform contact surfaces OEM matched 66mm 67mm oversize bore dimension , aligned edge layout to fit cylinder housing tightly