O.S. Engine OS29123100 Cylinder Liner 120AX Replacement Cylinder Part  [OS29123100]

Cylinder Liner for 120AX Engines

This cylinder liner is an RC-scale replacement component identified by the model number OS29123100 and intended for use with the 120AX engine family. It serves as the wear surface inside the engine sleeve and is supplied as a single replacement part for rebuilds or routine servicing of model engines.

Installation is straightforward for experienced model engine builders: remove the engine head and piston assembly, extract the worn liner, inspect mating surfaces, and fit the replacement liner following standard engine reassembly practice. Proper cleaning and light inspection of the piston and ring face are recommended before reinstalling to ensure consistent compression and sealing.

In tuning and maintenance workflows the liner's role is to restore internal geometry that affects compression and combustion behaviour at RC scale, so replacing a worn liner is a common step when restoring performance or preparing an engine for detailed tuning.

As a direct replacement cylinder liner for the 120AX series, this part is intended for RC model engine maintenance and rebuilds; use it when wear or scoring affects compression to return the engine to serviceable condition.