O.S. Engine OS40960100 Valve FS-95V for FS-series RC glow engines  [OS40960100]

FS-95V valve for FS engines

This FS-95V valve is an RC-scale replacement part produced under the O.S. Engine designation OS40960100 and intended for use with FS-series glow engines in model aircraft and other RC applications. The component is described as a valve assembly with a precision ground steel stem that serves as a direct replacement during routine maintenance.

Compatibility is limited to FS-series O.S. glow engines that use the FS-95V type valve; confirm fitment against your engine's parts list before installation. This article does not list specific chassis or engine model numbers beyond the FS-series designation, so cross-check with factory documentation when in doubt.

Installation overview: remove the cylinder head and valve train components following the engine maker’s service procedures, replace the valve assembly, inspect valve seat contact and clearance, then reassemble and perform a controlled bench run to verify sealing and idle characteristics. Avoid forceful seating; correct valve-to-seat contact and proper clearance are essential for predictable running and tuning.

Tuning and service role: the valve itself does not change carburetion or ignition timing, but a properly seating valve preserves compression and steady idle, which aids precise needle adjustments and consistent tuning. Regular inspection of valve surfaces and stem wear helps prevent compression loss and performance drift.