Crankshaft Polini Minarelli Vertical 10mm pin

Polini For Race reinforced Crankshaft for Minarelli Vertical engines.

The crankshaft is one of the parts that withstands the greatest load in a tuned 2-Stroke engine. Each combustion stroke transmits the force from the piston to the connecting rod and crankshaft, and the more the RPM, compression, and power increase, the greater the inertia loads borne by the entire assembly.

Polini uses a reinforced connecting rod and a 10 mm piston pin, maintaining the size used in numerous original Minarelli Vertical configurations. The assembly is supplied with the needle bearing suitable for the 10 mm pin.

In addition, the crankshaft is balanced to reduce vibrations and mechanical losses and receives a heat treatment intended to increase its strength. In a high-revving engine, proper balancing not only improves operation: it also reduces the stresses transmitted to bearings and crankcases.

Polini specifies this crankshaft for setups with 50cc and 70cc cylinders, making it a good foundation for tuned Minarelli Vertical engines where the original crankshaft is starting to become a weak point.

The 10 mm pin makes it possible to maintain compatibility with pistons designed for this size, making it an especially interesting option for both original-configuration engines and Sport builds.

During installation, we also recommend replacing the crankshaft bearings and seals and properly checking the axial play and the alignment of the assembly. In a tuned engine, reusing worn bearings can quickly compromise a new crankshaft.

Technical characteristics

• Manufacturer: Polini.
• Range: For Race.
• Reference: 210.0049.
• Engine: Minarelli Vertical 50 2-Stroke.
• Engine families: CY / MY / CW.
• Piston pin: 10 mm.
• Stroke: original.
• Connecting rod: reinforced.
• Balancing: specific to reduce vibrations.
• Treatment: heat treatment to increase strength.
• Needle bearing: included for 10 mm pin.
• Recommended application: 50cc / 70cc cylinders.
• Manufacturing: Made in Italy.

Compatible engines

• Minarelli Vertical 50 2-Stroke CY
• Minarelli Vertical 50 2-Stroke MY
• Minarelli Vertical 50 2-Stroke CW