Vespa PK 125 [1982-1991] - crankshaft with pin ø 15, connecting rod 97, stroke 51 mm and rotating valve and - cone ø 20

MALOSSI crankshaft for Vespa PK 125 with rotating valve

The MALOSSI crankshaft is designed for the Vespa PK 125 built between 1982 and 1991. It combines a robust construction with a design for drive units with a rotating valve inlet that is tailored to the small frame engine.

Function and construction

In this version, the intake phase is integrated into the half-crank within the circular mass structure. The resulting inward inclination supports efficient fluid dynamics while maintaining the external shape of the crankshaft. To support smooth running and stability, MALOSSI uses tungsten parts as counterweights in the crankshaft.

The crankshaft is made from reinforced aviation-grade steel and vacuum cast. The “Viper Head” shape of the connecting rod reduces weight while maintaining the required rigidity. The design of the thread on the gearbox side as well as the position and design of the wedge were also coordinated to ensure a robust construction.

Technical data

• Bolt: ø 15
• Connecting rod length: 97
• Stroke: 51mm
• Design: rotating valve
• Cone: ø 20
• Material: reinforced aviation grade steel
• Manufacturing: cast in vacuum
• With specially designed nuts

Vehicle assignment and notice

Suitable for Vespa PK 125, built between 1982 and 1991. The crankshaft is intended exclusively for racing in specially designated locations in accordance with the regulations of the relevant sports authorities. To ensure professional selection and installation, the vehicle and engine-specific requirements must be taken into account.