FSa-81 Replacement Rocker Arm OS47161100 for FS-Series Engines by O.S. Engine  [OS47161100]

Part Description and Compatibility Notes

This item is supplied under the O.S. Engine OS47161100 part number as a direct replacement for FSa-81 style rocker arms. Intended for FS-series RC engines, it transmits camshaft movement to the valve train and is suitable for maintenance, repair, or tuning tasks on nitro models.

Focus is placed on fit and reliable function rather than detailed measurements. Before installing, confirm the engine part code matches OS47161100 to ensure compatibility; replacement is typically performed when valve actuation shows wear or during routine engine servicing. The component is presented as an OEM-fit option to restore correct valve operation on FS-series assemblies.

Installation notes: remove the rocker cover, inspect rocker geometry and valve clearance, fit the new arm ensuring unobstructed movement, and then recheck engine timing and idle settings on the model prior to full running. Keep this part for model use only.