O.S. Engine OS44303200 Precision Replacement Piston FSa-72  [OS44303200]

High-precision piston for O.S. engines

This piston is supplied as a direct replacement for O.S. Engine items marked with the FSa-72 designation. It is intended for RC glow-engine service and renovation, and users should confirm fitment against the engine model code before ordering.

Use this piston to restore compression, exchange worn internal parts, or refresh the engine. It serves as the moving sealing component inside the cylinder and directly affects compression, ring seating, and engine response; correct bore dimensions and ring condition are essential for proper function.

Installation follows standard engine teardown procedures and calls for a clean workspace, correct ring orientation, and light lubrication during break-in. Refer to the engine service manual for exact measurements and torque values rather than relying on general guidance.

This OEM-branded piston is intended for hobbyists and technicians carrying out maintenance or repairs on compatible O.S. Engine glow engines; verify fitment before purchase.