70cc Evolution Racing cylinder kit from Polini. Aluminium build, sharp timing and modular high compression cylinder head give maximum performance. Suitable for Piaggio, Gilera, Aprilia & Derbi Scooter with water-cooled Piaggio 2-stroke engines (LC). It is supplied as a complete kit including cylinder head and necessary mounting hardware. In addition are several base gaskets better dial in the squish and a 12 mm little end bearing. A larger carburettorand a racing exhaust system is recommended. Bore: 47.6. Material: Aluminium with hard-chromed lining. Diameter of gudgeon pin: 12mm. Stroke: 39.3mm