Polini Corsa 47mm (70cc) Vertical Minarelli Big Bore Cylinder and Head Kit. Kit includes aluminum cylinder, aluminum cylinder head, piston, rings, piston pin, cir clips, head gasket, base gasket, exhaust gasket, exhaust studs, carbon fiber reed and #88 carb jet.
When you use this Polini 47mm Big Bore Kit in conjunction with your stock crankshaft you will increase your total displacement to 70cc! The manufacturer claims 9.7bhp at 10,800RPM is possible with this kit.
Fits Yamaha Zuma CW50 "Pre-Bug" Vertical Engines from 1989-2001.