O.S. Engine OS45561110 Rocker Arm for FS-120SIII and FT-300 Engines  [OS45561110]

Rocker arm for FS series engines

This O.S. Engine rocker arm is an RC-scale replacement component designed specifically for the FS-120SIII and FT-300 engine designations listed in the product name. It serves the discrete function of transferring cam motion to the valve train in these model engines, and is intended as a service or spare part for routine maintenance and repair of glow-powered RC models.

Compatibility is limited to the engine codes shown in the product title, so confirm fitment before installation. The part is supplied as a single pcs unit suitable for replacing a worn or damaged rocker arm in the specified engine assemblies.

Installation requires basic engine disassembly and familiarity with small fasteners and bearings common to RC engine work; use proper thread locking practices and torque control appropriate for model engines. This component influences valve actuation consistency, so check valve clearance and timing after fitting to ensure expected running behavior during tuning.