135cc Evolution Racing cylinder kit with reed valve inlet from Polini. Sharp timing and single-piece manufacture ensure the cylinder head gives high compression and maximum performance. Suitable for 125cc Vespa Primavera 2-stroke and Primavera ET3 2-stroke maxi-scooters. It is supplied as a complete kit including cylinder head and necessary mounting hardware. A larger carburettorand a racing exhaust system is recommended. Displacement: 130cc. Bore: 57mm. Material: Aluminium with hard-chromed lining. Diameter of gudgeon pin: 15mm. Stroke: 52.8mm. Compression ratio: 13.5:1