The first series of 50cc Piaggio 4-stroke engines came with a crankshaft that used the side of the belt with a 25x56x12mm crankshaft bearing. It was then changed to the internal diameter of 20mm, now common on 50 Piaggio engines. For these rather rare engines with 25mm, we offer this as a robust replacement crankshaft which is of good quality in its given range. Matching set of crankshaft bearings: for comparison purposes 38330 OEM Number: 969203