O.S. Engine OS21230010 Crankshaft Ball Bearing R CZ-11PS for Model Engine Fit  [OS21230010]

Bearing fitment and compatibility notes

This O.S. Engine OS21230010 crankshaft ball bearing R CZ-11PS is supplied as an exacting replacement for crankshaft journals in O.S. model engines. It functions as a wear component that supports the journal, lowers friction, and preserves rotational precision under load.

Before buying, compare the bearing dimensions with your engine crankshaft and housing to confirm compatibility. Proper installation requires a clean shaft and bore, and the bearing should be pressed in squarely using a bearing driver or a press rather than hammered.

Installing a fresh crankshaft bearing during servicing can reduce vibration, restore a smooth rotational feel, and help maintain consistent timing. Check bearings periodically for roughness, noise, or side play and replace when limits are reached.