Rotor Guide Spacer for R/C Engines (40L, 55HZ) - O.S. Engine OS25881220  [OS25881220]

How the washer supports rotor alignment

This rotor guide washer is made for R/C-scale engine assemblies and acts as a precise spacer inside the rotor stack. It preserves component positioning through teardown and rebuild, helping maintain correct alignment during routine servicing or tuning tasks on nitro-style models.

Model makers and workshop technicians employ the washer to control end-play and keep rotating elements concentric by placing it between rotor parts. That positional control can cut down on guesswork when you are adjusting timing or balancing rotating components.

Installation notes: perform engine head or rotor housing removal as per the manufacturer's service steps, insert the washer where required in the rotor stack, and check clearances against the engine's service specifications. Use thread-lock or specified torque only where the manual indicates; the washer is a passive spacer and does not replace bearings or seals.

Tuning advice: whenever you modify fuel mixture, ignition timing, or ports, re-verify rotor alignment. Even small alterations in stack height influence rotor balance and engine consistency, so include the washer in your measurement checks rather than expecting a performance change.