21F-Compatible Piston Pin OS22406001 by O.S. Engine  [OS22406001]

Precision piston pin for rebuilds

This O.S. Engine OS22406001 piston pin is specified as a replacement item for RC engine rebuilds and service work. It is intended for 21F-series engines and functions as the pivotal link between the piston and connecting rod in the engine mechanism.

The guidance emphasises correct fitment and workshop checks rather than providing dimensional specs. During rebuilds verify the piston pin translates smoothly in the piston small end and seats true in the wrist pin bore prior to final assembly. Employ accepted engine service technique and proper tools to avoid surface damage or misalignment when installing the pin.

Installation notes:

• Clean all mating surfaces and remove contaminants before fitting.
• Confirm a light sliding engagement in the piston and small end; any excessive play or binding indicates incompatibility.
• Comply with the engine manufacturer's recommended assembly order and torque values for related fasteners.