O.S. Engine OS27407000 Cover Plate for 75AX Crank Case Replacement  [OS27407000]

Service cover for 75AX crank case

This cover plate is an RC-scale crank case component made for service and repair of O.S. Engines 75AX series units. It serves as a direct replacement part to restore the engine casing surface and maintain proper sealing during routine maintenance or part swaps.

Fit and installation are straightforward for model workshop work: confirm mating surfaces are clean, align the plate with the crankcase bores and bolt pattern, and use the original gaskets or seals as required. Avoid overtightening fasteners and follow the engine’s service practice for torque and sequence to protect threads and ensure a uniform seal.

For tuning and performance checks the cover plate’s role is simply to preserve crankcase integrity so compression and run characteristics remain consistent after maintenance. Keep a spare on hand as a field-replaceable item for quick repairs during track or club sessions.