Upgrade Cylinder Liner OS29123100 for O.S. Engine 120AX  [OS29123100]

Restore Compression for Performance Tuning

This cylinder liner, model OS29123100, is supplied as the replacement bore sleeve for the 120AX engine family. It functions as the internal wear surface and is provided as a single service component for engine rebuilds or maintenance tasks.

Fitting the liner typically requires removing the engine head and piston assembly, extracting the old sleeve, checking mating surfaces for damage, and installing the new liner with care. Clean mating faces and a light inspection of the piston and ring face will help achieve repeatable compression after reassembly.

Replacing the liner returns the engine's internal geometry to a known state, which is especially useful when you are preparing the engine for tuning work. A fresh sleeve helps stabilise compression and combustion characteristics so tuning changes are based on predictable mechanical condition.

Intended as a direct replacement for the 120AX line, this cylinder liner is used in maintenance and rebuilds to recover compression and provide a stable platform for tuning and setup.