When sourcing gas scooters, the engine is the core component. You must verify if the engine is a 4-stroke air-cooled or liquid-cooled system, as 4-stroke engines are more fuel-efficient and meet stricter emission standards. For a standard Vespa-style model, look for displacement options of 50cc, 125cc, or 150cc depending on your target market's licensing laws. Ensure the scooter utilizes a CVT (Continuously Variable Transmission) for smooth acceleration and check that the fuel tank capacity is at least 5-7 liters to ensure a practical commuting range.