All 50 cc Runner models were restricted to 28 mph (45 km/h) to comply with European law.

The direct injection Runner Purejet 50 was released in 2003 with lower emissions.

The biggest difference between the FX (FXR) and the SP is the FX had a 9 L (2.0 imp gal; 2.4 US gal) petrol tank and battery stowed near the spark plug and a rear drum brake.

[8] The four-stroke Runner was equipped with a liquid cooled, four valve version of Piaggio's LEADER engine.

On two-stroke models the oil filler hole has now been moved under the front of the seat, and there is a basic tool in the small compartment at the back.