YS Engine YSF1231 F120 Back Plate Mounting Screw  [YSF1231]

Back-plate Mounting Screw for F120

This YS Engine back plate screw is supplied as a direct spare for the F120 back plate assembly, listed under model YSF1231. It functions as the fastener that clamps the engine rear cover to the crankcase and is intended for service replacement where OE screws are damaged or missing.

Fitting guidance: align the screw with the back plate boss and hand-start to ensure correct thread engagement; if you detect unusual resistance, withdraw and inspect the mating thread. The part is intended to restore mechanical retention and sealing rather than alter engine performance.

Fit note: named compatibility is F120; verify part YSF1231 corresponds to your back plate layout prior to purchase. The screw is suitable for routine maintenance and quick swaps during bench work or on-track fixes.