Cylinder kit 47mm for BWS50

This is Taiwan CHARMO OEM big bore cylinder kit 47mm and 10mm pin with 7 air-port windows, what helps for air easy in and out therefore there is an increase in speed. 70cc, tuning version for modification of Yamaha Bws50, vertical 2JA engine. This is the best kit for upgrade Bws50. Can be used with standard crankshaft and long stroke. This kit includes: 70cc cylinder big bore, piston 47mm, piston rings, 0 rings, gaskets.