21M and 21XM Carburettor Metering Needle - O.S. Engine OS22082350  [OS22082350]

Replacement metering needle for 21M/21XM

This O.S. Engine metering needle is a direct replacement carburettor component intended for use with 21M and 21XM series RC engine carburettors. It regulates fuel flow through the needle valve so you can refine the mixture for different running conditions in nitro-powered RC models.

The tip is stainless steel to resist wear at the seating surface, while the shaft and taper are manufactured to match the original fit dimensions for the stated carburettor types. Installation involves removing the carburettor top and swapping the needle; final calibration should be completed track-side with small idle and main mixture adjustments to achieve the preferred response.

Choose this part when you need a like-for-like replacement or when a worn needle is affecting mixture consistency. This description applies to RC-scale engines only and not to full-size engines.