O.S. Engine OS29025400 Silencer Mounting Screw CSM4X17 for 855 108FSR  [OS29025400]

Silencer mounting screw for nitro and small RC engines

This mounting screw is specified in the manufacturer part code as CSM4X17 and listed alongside identifiers 855 and 108FSR in the original product name. It is a dedicated RC-scale fastener intended to secure a silencer to an RC engine exhaust assembly, holding alignment under vibration and during setup adjustments.

Use this part as a direct replacement when your parts list or spare parts diagram references the same part code string. Installation is focused on proper thread engagement and seating to maintain exhaust alignment; verify the part code before fitting and inspect threads for wear or damage prior to reuse.

As a small replacement fastener, its role in tuning and maintenance is practical rather than performance altering. It keeps the silencer located and reduces movement that can affect exhaust sealing and consistency during engine adjustments.