YS Engine YSF3177 FZ63S Under Cover Gasket Replacement for RC Engines  [YSF3177]

FZ63S under-cover seal overview

This YS Engine YSF3177 under cover gasket is a replacement part designed to seal the FZ63S engine's lower cover. It creates the interface between the engine under cover and the mating surface to reduce leaks and maintain proper internal conditions during running and workshop checks.

Fitting is straightforward for hobby technicians: remove the under cover, clean mating faces of oil and debris, lay the gasket flat to avoid folds, then refit the cover while tightening fasteners evenly to the manufacturer's recommended torque. Avoid over-tightening bolts and inspect the sealing surface for nicks or distortion before installing the new gasket.

While the gasket does not modify engine power, a correct seal supports consistent compression and prevents oil loss or contamination that can change engine behaviour. Replace the gasket whenever the under cover is removed for service or if you observe visible wear or deformation.