Curare very thanks for your advico for gear ratio to my engine.
When i rebuild my engione i think about gera ratio 23/65 but 22/65 its better combination for town and for long distance (engine polini177, carb si24/24 gear Cosa 200, exhaust pinasco. Last weekend i tested my vespa on the road, everyday im ride in town - i'm very happy Curare again very thanks!