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

Service retainer for FS-series engines

This valve spring retainer appears in the O.S. Engine parts catalogue under model OS45560310 and the FS-120S reference. It secures valve springs on FS-series glow engines and is intended for use during regular servicing, repairs, or full rebuilds.

By holding springs correctly seated and aligned, the retainer helps prevent valve timing irregularities when inspected as part of normal maintenance. Always match OS45560310 to the service parts list for your FS-120S and check adjacent valvetrain components for wear before installation.

The retainer itself will not modify valve timing but provides stable spring retention when changing springs or setting clearances during tuning. Observe workshop best practices when working with small valvetrain parts and follow the recommended service schedule.