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

Replacement piston ring for nitro model engines

This piston ring is a replacement part made for cylinder and piston assemblies from O.S. Engine. It performs the essential task of sealing the combustion chamber in nitro RC engines to help preserve compression and promote steady performance during use and tuning.

Installation guidance: inspect the piston and cylinder for scoring or wear before installing the new ring, position the ring gap as the engine manual specifies, ease the ring onto the piston without bending it, and confirm the piston moves freely in the cylinder prior to final reassembly.

Tuning impact: a correctly seated piston ring helps maintain repeatable compression and controls oil consumption, which influences throttle response and idle consistency; check compression readings and fine tune needle settings only after you verify correct ring seating and piston fit.