Replacement Carburettor Needle OS27481900 - O.S. Engine (FS-61, FS-70S, FS-80, FS-120SE)  [OS27481900]

RC carburettor needle for O.S. Engine

This needle valve assembly is an RC carburettor component intended for the engine models named. It enables the operator to set low-speed fuel metering so the mixture can be tuned for smooth idle and throttle response.

Compatibility is restricted to the engine model codes quoted in the name: FS-61, FS-70S, FS-80, FS-120SE. Always verify part numbers with the engine's exploded parts diagram or manufacturer literature before assuming interchangeability.

Installation notes - general guidance:

• Work over a clean bench and remove fuel from the system to reduce contamination during service.
• Fit the replacement needle using the original carburettor orientation and resecure any retaining clips or seats per the engine references.
• After fitting, make cautious needle adjustments and confirm idle behavior and throttle response in a safe area.

Tuning and maintenance tips:

• Use very small adjustments when tuning the low-speed needle to find a balanced idle and linear throttle feel.
• Regularly inspect the needle tip and seat for varnish, scoring, or wear; clean with a solvent suitable for carburettors if required.
• Keep a written record of baseline needle settings so you can return to known values during tuning sessions.