Precision Rocker Arm Shaft YSF1215 for YS Engine 120 140 160  [YSF1215]

Precision rocker pivot for 120/140/160 engines

This replacement rocker arm shaft is an RC valve-train component intended for YS Engine variants labelled 120, 140 and 160 in the product title. It provides the pivot point for rocker arms, conveying cam action to the valves and maintaining correct alignment under varied running conditions.

Installation notes: remove the cylinder head and rocker assembly as per your engine's factory procedure, inspect rocker arms, retainers and mating surfaces for wear before installing the shaft, ensure correct seating and minimal endplay, and keep any original shims or spacers if still serviceable. Use light assembly lubrication and confirm unrestricted rocker travel before completing the rebuild.

Tuning and maintenance role: this shaft is supplied as a service part for rebuilds or replacement after valve-train wear. A true, undamaged shaft supports repeatable valve timing and reduces the risk of premature wear on rocker bores and valve guides. Maintain cleanliness around the area and apply thread locking only where the engine guidance specifies.