O.S. Engine OS25881700 40L Carburettor Mount Retainer  [OS25881700]

Essential retainer summary

The O.S. Engine OS25881700 carburettor retainer is an aftermarket replacement part intended to hold 40L carburettors in nitro engine assemblies. Its primary job is to keep the carburettor positioned so throttle linkage and needle adjustments stay consistent while running.

Installation should be familiar to hobby technicians: secure the retainer to the engine flange using the existing mounting points, ensure the carburettor sits square, then align the throttle arm prior to tightening. Use the same screws and hand-tighten until firm, and re-check after a brief run to confirm the fasteners remain secure.

When tuning, this retainer reduces small positional shifts that can change air and fuel mixture, aiding in idle consistency and throttle response. It also supports repeatable reassembly when swapping carburettors or carrying out routine maintenance.