Precision Rocker Support for FS-120S - OS45561410 by O.S. Engine  [OS45561410]

Maintaining rocker alignment on the FS-120S

This rocker support is intended for the O.S. Engine FS-120S and is identified by part number OS45561410. It functions as a service replacement to keep rocker geometry stable, limiting end play and helping preserve precise valve actuation.

To fit the support, remove the engine cover or associated mounting hardware, install the OS45561410 replacement, and reassemble while checking clearances and rocker movement. Work carefully with the small components and verify unobstructed motion before completing reassembly.

During tuning and setup, the support aids in maintaining repeatable valve geometry and can reduce timing variation linked to worn rocker seating. Include the part in inspections when addressing issues such as tapping noises or uneven valve travel after repairs or break-in.