O.S. Engine OS27414020 Cover Plate Gasket O-Ring for S-36 and 75AX Crankcase Seal  [OS27414020]

Crankcase Cover O-Ring for Model Engines

This O.S. Engine OS27414020 O-ring serves as a cover plate gasket for the crank case of S-36 and 75AX style model engines. It acts as a replacement seal to help keep the crankcase closed and maintain the engine's intended internal environment during normal use.

Installation is straightforward for hobby technicians: remove the cover plate, clean mating surfaces of old gasket residue and oil, seat the O-ring into the cover groove, then reassemble using the manufacturer's torque recommendations for case fasteners. Take care not to pinch the ring during fitting and inspect the groove for burrs or trapped debris that could compromise the seal.

During tuning and routine maintenance, a correctly seated cover plate O-ring promotes stable compression and reduces air leaks that can upset idle stability and throttle response. Replace the O-ring whenever you remove the cover plate for service, after long periods of use, or if the ring shows hardening or visible damage.