Crankshaft -MAZZUCCHELLI Racing (rotary valve), 51mm stroke, 97mm connecting rod- Conversion shaft Vespa PK50 XL/XL2 to 125cc (Ø 20mm cone).

Mazzucchelli Racing crankshaft for PK50 conversion to 125

To achieve higher engine speeds, you should use the racing shaft. The extended intake timing allows the engine to rev much more freely. This measure is particularly noticeable with high-speed cylinders.

The quality of the crankshafts is very good and they can withstand even the highest speeds. They are an ideal addition, especially for the larger displacement engines from 125 cc upwards, to extend the usable speed range of racing cylinders without spitback in the lower speed range.

These engines offer both a decent torque over the entire speed range and free revving without the engine running out of air on inclines.

The PK XL shaft also offers the enormous advantage that it has a very stable cone and can therefore withstand much higher forces. It also allows the use of ultra-light pole wheels, which can achieve better acceleration behavior.