Mazzucchelli Racing crankshaft with full cheeks for Vespa PX200
The full cheek shafts were primarily developed to improve the pre-compression ratio and thus increase the cylinder filling via the increased pressure in the crankcase. By installing the full cheek, however, the effective cross-section of the intake tract is greatly reduced. This considerably reduces the possible filling ratio in the upper speed range, and engines equipped with such a crankshaft usually drop sharply in performance at 7,000 rpm.
DE | €
