FSa-72 Piston Ring OS44303400 for O.S. Engine  [OS44303400]

Service piston ring for model nitro engines

This piston ring is a service spare for O.S. Engine piston and cylinder assemblies. It provides the sealing function in the combustion chamber of nitro RC engines, supporting consistent compression and dependable running characteristics during use and tuning.

Installation reminders: examine the piston and cylinder bore for wear before fitting the new ring, set the ring gap according to the engine manual, ease the ring onto the piston without forcing it, and verify the piston moves freely in the cylinder prior to reassembly.

Tuning considerations: a correctly fitted piston ring promotes stable compression and oil control, influencing throttle response and idle stability; check compression measurements and only alter needle settings after confirming correct piston and ring fitment.