O.S. Engine FS-120S Valve Spring Retainer OS45560310  [OS45560310]

Replacement retainer for FS valves

This valve spring retainer is a direct replacement listed within O.S. Engine spare parts, identified as OS45560310 with association to FS-120S. It is designed to hold valve springs on FS-series glow engines and is suitable for engine servicing, repairs, or scheduled rebuilds.

Essentially, the retainer ensures springs remain seated and aligned while the engine runs, so including it in routine inspections helps reduce the risk of valve timing faults. Prior to replacement, verify that OS45560310 matches your engine's parts list and assess neighboring valve train components for wear.

During tuning operations, the retainer does not change valve timing but supports dependable spring retention when adjusting clearances or replacing springs. Always use careful handling for small valvetrain parts and adhere to the engine service recommendations.