50ST Series Crankshaft — YS Engine YSS1011 Replacement  [YSS1011]

50ST series crankshaft details

This YS Engine YSS1011 crankshaft is supplied as a replacement part for engines identified by the 50ST designation. The content concentrates on correct fitment and assembly for the 50ST family without claiming wider compatibility.

The crankshaft is the principal rotating assembly; correct alignment, bearing seating, and lubrication are essential at installation. Consult the engine service manual and parts diagrams to confirm tolerances, end-play, and seal needs before refitting.

In workshop practice, the crank is described by its mechanical role rather than performance. Inspect for runout, check journal wear, and ensure the connecting rod is correctly keyed and secured during rebuilds.

When servicing a 50ST-designated engine, use this YS Engine YSS1011 crankshaft as a replacement, verifying bearing sizes and clearances and following standard break-in and lubrication practice.