O.S. Engine OS42525310 O-ring S-25 silencer gasket replacement for RC mufflers  [OS42525310]

Silencer O-ring for RC engines

This O-ring S-25 silencer gasket from O.S. Engine is an RC-scale replacement seal intended for mufflers and silencers that use the S-25 style O-ring, listed with part references F-6020 and FSa-155. It is supplied as a single replacement sealing component to restore a tight exhaust joint on model engines and reduce blow-by at the silencer interface.

Installation is straightforward: remove the silencer, inspect the mating face for burrs or carbon build-up, seat the O-ring into its groove, and reassemble ensuring even compression. Use care to avoid twisting the ring during fitment and check for exhaust leaks on first run. This part should be treated as a consumable during routine maintenance of RC glow engine mufflers.

In tuning and setup, a correctly seated silencer gasket helps maintain consistent backpressure at the exhaust outlet, which can assist in stable idle and throttle response on RC models. Replace the O-ring if it shows hardening, cracking, or permanent deformation.