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

Service and fit notes for GGT10 pins

Designed as an RC-scale replacement, this piston pin suits O.S. engine assemblies bearing the GGT10 designation. It is the primary wear surface between piston and small-end rod, so its integrity matters for piston centring and smooth reciprocation in running engines.

Inspect the pin during glow engine service for evidence of scoring, discoloration, or play within the rod bore. Replace any pin that no longer provides a correct, snug fit to maintain compression and stable piston travel.

Installation guidance: follow your engine's disassembly procedure for the piston and connecting rod, verify retaining clips and hardware are undamaged and fully seated, then fit the pin ensuring it moves freely without excessive side play. Use a light lubricant compatible with glow engines on reassembly and check free rotation prior to refitting the engine to the model.

Tuning considerations: although a small part, the piston pin helps preserve consistent piston alignment and so contributes to repeatable engine response after rebuilds. Changing pins during a rebuild removes a variable when diagnosing irregular running.