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

Sealing ring for nitro engine assemblies

This steel piston ring is intended as a service spare for O.S. Engine cylinder and piston assemblies. Its role is to seal the combustion chamber in nitro RC engines, helping to keep compression levels reliable and engine operation consistent during running and setup.

Fitment notes: check the piston and bore for wear or damage before installing a new ring, orient the ring gap according to the engine instructions, ease the ring onto the piston carefully to avoid deformation, and confirm unobstructed piston travel in the cylinder before completing reassembly.

Role in tuning: proper ring seating supports stable compression and oil control, which affects throttle feel and idle; verify compression and only adjust needle settings after confirming correct ring and piston condition.