O.S. Engine OS4A408000 Drive Washer GGT10 Engine Crank Shaft Part  [OS4A408000]

Drive washer for crankshaft

This O.S. Engine drive washer is an RC-scale crank shaft component intended to control axial spacing and maintain consistent alignment between rotating engine parts. It is a compact replacement/maintenance item that belongs with engine crankshaft part sets used on small nitro or glow model engines.

Installation is straightforward for experienced hobbyists: seat the washer flat against the mating surface on the crank assembly, confirm even contact all around, and verify axial play after reassembly. Its role in tuning is to preserve correct gear and drive clearance so timing and throttle response remain repeatable during set-up and track use.