O.S. Engine OS4A406000 GGT10 Replacement Piston Pin  [OS4A406000]

Overview of the GGT10 pin

This piston pin is supplied as an RC-scale replacement for O.S. engine assemblies marked GGT10. It forms the critical wear surface between piston and connecting rod, influencing piston centering and the smooth back-and-forth motion of the engine.

When overhauling a glow engine, inspect the pin for scoring, discoloration, ovality, or play within the rod bore before reuse. Replace any pin whose wear compromises fit or movement to help retain compression and consistent piston travel.

Fitting advice: disassemble the piston/connecting rod subassembly according to the engine service routine, confirm circlips and retention components are intact and correctly seated, then insert the pin ensuring a smooth, snug fit. Use light, engine-compatible lubrication on reassembly and verify free rotation ahead of full engine refit.

Role in tuning: small components such as the piston pin influence repeatable piston alignment and therefore help stabilize engine response after rebuilds or part changes. Swapping worn pins during rebuilds removes a common variable when troubleshooting inconsistent performance.