Cylinder Polini Sport 70cc, Aprilia SR50 Sport (Aprilia engine with carb)

This 70cc Sport cylinder is made of grey cast iron; it’s very high-torque and, above all, with massive bottom end punch. Ideal for everyday use. Its power is mainly based on the increase in capacity, which makes it a reliable cylinder. The original carburettor can be kept, but the main jet should be increased by around 5–10% (just as a rule of thumb).