Crankshaft Drive Washer for RC Engines O.S. Engine OS4A408000  [OS4A408000]

Precision drive washer for crankshaft assemblies

This O.S. Engine drive washer is an RC-scale crank shaft component made to control axial spacing and keep rotating engine parts correctly aligned. It is a compact replacement and maintenance item matched with crankshaft part sets used on small nitro or glow model engines.

Installation is simple for experienced hobbyists: seat the washer flat against the mating surface on the crank assembly, confirm even contact all around, and check axial play after reassembly. The washer helps preserve correct gear and drive clearance so timing and throttle response remain consistent during setup and on the track.