120/140 Class Rocker Arm Shaft Screw - YSF1216 for YS Engine  [YSF1216]

Durable rocker shaft fastener for model engines

The YS Engine YSF1216 is an RC rocker arm shaft screw intended for 120 and 140 class model engines, as indicated by the listing. It functions as a service replacement to secure the rocker arm shaft and maintain correct valve linkage alignment during maintenance or rebuilds.

Operationally the screw fixes the rocker arm shaft so the rocker arms can convey cam or valve motion into the valve train. When preparing to reuse the part inspect the thread form, screw head condition, and any signs of corrosion or wear; replace if integrity is compromised to preserve accurate valve motion.

Fitting guidance: ensure the rocker arm shaft is installed without lateral load, confirm smooth rocker travel after tightening, and verify clearances during the first run. This item is intended for maintenance and rebuild use rather than as an upgrade for increased power.