Crankshaft Evolution (stroke 54mm / piston pin 15mm) - Polini

Evolution Crankshaft (54mm / 15mm) Polini for the following applications: Vespa Primavera ET3 125 AIR 2T (1967-1983).

The Evolution crankshaft can only be used if the engine is equipped with the new reed valve cylinder (140.0227). The circular masses significantly reduce noise from the crankcase and increase the pre-compression of the gas-air mixture. Balancing is achieved through the use of tungsten inserts and aluminum caps to reduce volumes. The assembly of this new product allows for achieving a displacement of 152cc.

Technical specifications:
- Small needle bearing included (15x19x20mm);
- Connecting rod: 105 mm;
- Stroke: 54 mm;
- Piston pin: 15 mm;
- Class: Race;
- Type: Evolution.