FS-200S Crankshaft Drive Washer OS44508000 - O.S. Engine  [OS44508000]

FS-200S drive interface washer

This drive washer serves the FS-200S engine family and is listed under the O.S. Engine model OS44508000. It locates the drive coupling at the crankshaft end and helps preserve the intended axial clearance in normal running conditions.

Workshop fitting is simple: slide the washer onto the crank flange until it seats against the crankcase face or an adjacent spacer, verify the coupling runs true, and then measure endplay using a feeler or dial gauge. If excessive play is present, recheck mating surfaces and nearby shims before modifying washer thickness.

When tuning or servicing, the washer reduces unwanted axial movement that can lead to coupling misalignment or uneven gear wear. Inspect the washer for deformation or wear during rebuilds or when diagnosing vibration or premature coupling deterioration.