Genuine OS factory cylinder liner for the FS-56α (FS-56A) four-stroke glow engine. The liner is the precision-honed bore the piston runs in — the heart of the engine's compression — and replacing it is the cure for an engine that's lost pinch through wear, scoring from ingested dirt, or corrosion from being stored wet with old fuel residue.

A liner swap effectively returns the bottom of the compression system to factory condition. Because piston and liner wear together as a matched pair, inspect the piston while the engine is apart — fitting a new liner against a worn piston gives away much of the gain, so budget for both if the piston shows wear or discolouration. Refit with a new head gasket, as the original will have crushed in service.

After assembly, treat the engine as new: run in rich for the first few tanks to let the fresh surfaces bed together before leaning out to full performance.

Specifications

Brand: OS Engines (Japan)
Part number: 44603100
Type: Cylinder liner
Suits: OS FS-56α (FS-56A) four-stroke