O.S. Engine OS22406001 Piston Pin 21F Replacement Part  [OS22406001]

Piston pin for RC engines

This O.S. Engine OS22406001 piston pin is presented as a straightforward replacement component for use in RC-scale model engine rebuilds and maintenance. The part name indicates compatibility with 21F-series applications and it serves the core mechanical role between piston and connecting rod in a model engine assembly.

The write-up focuses on practical fit and service considerations rather than specifications. When performing a rebuild, confirm the piston pin slides freely in the piston small end and seats correctly in the wrist pin bore before final assembly. Use standard engine service practice and proper tools to avoid scoring or misalignment during installation.

Installation notes:

• Clean mating surfaces and remove debris before fitting.
• Check for smooth, light sliding fit in the piston and small end; excessive play or tightness indicates mismatch.
• Follow the engine manufacturer's recommended assembly sequence and torque values for related fasteners where applicable.