120SR Engine Cylinder Liner YSS3005 - YS Engine  [YSS3005]

120SR Cylinder Liner Replacement Overview

This YS Engine YSS3005 cylinder liner serves as a direct replacement for engines in the 120SR class of RC glow motors. The text highlights the part's purpose during rebuilds, clarifying how it contributes to recovering compression and steady running at scale.

Intended for hobbyists experienced with small engine work, the liner requires head removal and inspection of the piston and ring seating to verify dimensional fit; any excessive wear or piston damage should be remedied prior to refitting the new liner.

Fit and check clearances on the bench as part of a careful maintenance routine before returning the engine to service to ensure consistent tuning results.