YS Engine YSS7146 O-ring Set for 61ST-H RC engines  [YSS7146]

O-ring set for 61ST-H

This O-ring set from YS Engine is an RC-scale spare part specified by model YSS7146 and referenced to the 61ST-H designation in the original product name. It exists to restore or maintain sealing surfaces on compatible 61ST-H engine assemblies used in radio-controlled models.

Use this kit when performing routine engine servicing or rebuilds where old or damaged O-rings are removed. Replacing degraded O-rings helps prevent fuel or crankcase leaks and preserves correct internal pressures during running. Confirm the 61ST-H marking on your engine before ordering to ensure fit.

Installation is a straightforward maintenance task for modellers familiar with RC engine disassembly, requiring careful cleaning of seating grooves, light lubrication of new rings to avoid twisting, and incremental assembly checks. This part supports maintenance and tuning workflows rather than performance gains by itself.