Rocker Arm Spare OS45561110 Compatible with FS-120SIII / FT-300 - O.S. Engine  [OS45561110]

Replacement rocker arm for FS engines

This rocker arm from O.S. Engine, model OS45561110, is a replacement component tailored for FS-120SIII and FT-300 engines listed in the title. It is responsible for converting cam motion into valve actuation in glow RC engines.

Please confirm compatibility with the explicit engine codes before purchase, as the part fits only the cited engine models. The supply is one pcs rocker arm intended for direct replacement of a damaged or worn unit in the specified assemblies.

Fitting typically requires disassembly of small engine components and competence with miniature fasteners; apply suitable thread locker and controlled torque when reassembling. After installation, recheck valve clearance and timing to maintain predictable running characteristics during tuning.