O.S. Engine OS22081811 Rotor Set Screw for 10FSR,10/15/25FP,FS20,FS40,21,31,RE  [OS22081811]

Rotor set screw overview

This rotor set screw is an RC-scale engine replacement part referenced by O.S. Engine OS22081811. It is intended for use with the model codes listed in the product name and serves the mechanical role of retaining the rotor assembly on compatible small-displacement RC engines.

Use this part as a direct maintenance or repair item when reassembling the crank/rotor area after service. Its purpose is to secure the rotor against axial movement, helping maintain alignment and consistent running behavior in model engines where this screw is specified.

Installation notes: verify the OS22081811 part number matches your engine manual or supplier listing before fitting, clean mating threads, and use an appropriate driver to avoid rounding. Apply light, controlled torque; excessive force can damage the screw head or mating threads. Inspect the seating during initial runs and retorque if necessary after break-in.

Role in tuning and upkeep: while not a tuning part per se, a properly secured rotor contributes to repeatable engine response by preventing rotor shift under load, which can otherwise affect idle stability and throttle consistency.