Naraku 50cc QMB139 4-stroke 52.4mm, Racing Big Bore Cylinder and Head Kit. Kit includes cylinder, piston, rings, piston pin, cir clips, cylinder head, head gasket, and base gasket.
When used in conjunction with a stock stroke of 41.4mm the total displacement comes out to 89.3cc! When used with a 44mm stroker crank, total displacement measures 94.9cc!