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

RC nitro piston ring replacement

This piston ring is supplied as a replacement component for O.S. Engine cylinder and piston assemblies. It seals the combustion chamber in nitro model engines, contributing to maintained compression and consistent engine performance during running and tuning routines.

Fitting advice: inspect the piston and cylinder for any scoring before fitting a new ring, place the ring gap as outlined in your service instructions, fit the ring gently onto the piston without forcing it, and make sure the piston slides smoothly within the cylinder before finishing assembly.

Tuning notes: a properly seated piston ring ensures repeatable compression and helps control oil migration, both of which influence throttle response and idle. Confirm compression readings and only tweak needles after you are satisfied with ring and piston fit.