MAZZUCCHELLI AMT 158 Crankshaft For Vespa 50 / PK - Ape / Special - Stroke 43 - Cone 19 - Connecting rod inside 87

Racing crankshafts are an essential and highly effective tuning step for optimizing any rotary valve engine. They allow the engine to reach higher rpm, giving it greater liveliness and agility. The prestigious racing crankshafts from the renowned Italian company MAZZUCCHELLI are distinguished by their tight manufacturing tolerances and limited bearing play, thus ensuring high-revving resistance and exceptional durability.

Unlike stock crankshafts, racing crankshafts feature a significantly extended input stroke, resulting in increased charge level. The crank arms are flow-optimized and polished, reducing turbulence and improving flow. A polished connecting rod and a lower connecting rod bearing, similar to a silver bearing, meet the highest performance standards. All crankshafts are supplied with superior connecting rod bearings.

Those looking to upgrade to electronic ignition should opt for the 20/20mm stroke crankshaft. It's recommended to use it in conjunction with a racing cylinder for a thicker, more stable cone. The ETS crankshaft is particularly suitable for high-revving engines equipped with high-performance cylinders or very lightweight flywheels, thus eliminating the risk of crank stub failure. A set of conversion bearings and the corresponding oil seal are included with the V50/PV/ET3/PK engine cases.

The RACE version of the connecting rod is reinforced and features additional lubrication holes at the top (for the 125 series only) and lubrication slots at the bottom, ensuring greater stability and allowing for increased rpm thanks to improved lubrication.

In conclusion, installing a racing crankshaft is not only a good idea in combination with a tuning cylinder, but can also lead to a significant performance boost even with an original cylinder. MAZZUCCHELLI stands for long-lasting and reliable products.

Racing Crankshaft Specifications:

- Type: Racing crankshaft

- Dimensions: 43mm diameter, 87mm stem

- Housing oil seal diameter: 19mm

- Bearing diameter: 20mm

- Cone with M10mm thread

- Including crankshaft bearing

Suggestions:

- New bearings, sealing rings and keys are essential

- Recommended seal, clutch, flywheel and nut kits

- Ideal for VMC rotary valve racing cylinders, as well as Pinasco, POLINI , MALOSSI , DR, and other high performance cylinders.