Needle Valve Assembly for OLD-10A, OLD-10D Carburettors - O.S. Engine OS21285900  [OS21285900]

Overview of the needle assembly for OLD-10 models

This needle valve assembly is an RC-scale carburettor replacement designed for the OLD-10A and OLD-10D carburettors. It provides the metering function needed to adjust fuel delivery when setting mixtures and during routine servicing of nitro RC engines.

Compatibility is restricted to the specified carburettor models, so confirm you have an OLD-10A or OLD-10D before ordering. When fitted the assembly supplies the adjustable needle interface that controls idle and part-throttle mixtures; swapping in a new assembly restores predictable needle response without altering other carburettor components.

Fitting the assembly is a standard carburettor service task: remove the carburettor top, extract the existing needle assembly, and install the replacement with correct seating, then check idle and throttle response. Make small, deliberate adjustments when tuning and test engine behavior in a safe outdoor environment for nitro RC operation.