Vespa PK S Automatic 125 [1984-1989] - crankshaft with pin ø 15, connecting rod 97, stroke 51 mm and rotating valve and - cone ø 20

MALOSSI crankshaft for Vespa PK S Automatic 125

The MALOSSI crankshaft is intended for the Vespa PK S Automatic 125 from the 1984-1989 model year range. Their design is tailored to drive units with rotating valve inlets and combines defined dimensions with design solutions for stable crankshaft function.

Design and technical features

• Bolt: ø 15
• Connecting rod: 97
• Stroke: 51mm
• Version with rotating valve
• Cone: ø 20
• Aerospace grade reinforced steel crankshaft vacuum cast
• Connecting rods in “Viper Head” shape to combine low weight with the required rigidity

In the version for the rotating valve inlet, the intake phase is incorporated into the inner half crank. The resulting shape supports pronounced fluid dynamics within the crankshaft. For balancing purposes, parts made of tungsten are inserted into the crankshaft as counterweights. This means that the stability of the shaft is taken into account in the design.

Vehicle assignment

Suitable for Vespa PK S Automatic 125, built between 1984 and 1989. The assignment refers to this vehicle and the complete year range mentioned.

Instructions for use

The crankshaft comes with special nuts. The product is intended exclusively for racing in specially designated locations in accordance with the regulations of the relevant sports authorities. When selecting and installing, the dimensions mentioned and the design for the rotating valve inlet must be taken into account.