O.S. Engine OS21781970 Needle 10LA & 15LA carburettor needles  [OS21781970]

Carburettor needles for glow RC engines

This O.S. Engine OS21781970 twin needle offering covers the 10LA and 15LA needle types used on small glow-model carburettors, sold as RC-scale replacement parts for model engine upkeep. The needles are intended to restore or replicate the factory adjustment interface in carburettors that accept 10LA/15LA style needles and to provide repeatable seating for tuning tasks.

Functionally the needle is a tuning interface: it sets the mixture and idle range by altering fuel flow at the carburettor needle valve. Swapping a worn or damaged needle helps eliminate erratic idle, uneven throttle response, or the need for excessive mixture compensation during setup. The part is presented as a direct replacement needle component rather than a multi-part assembly.

Installation and tuning notes: only fit this needle to carburettors designed for 10LA or 15LA needle types, confirm correct seating and smooth travel, and then adjust mixture and idle per your engine's established procedure. Make small incremental adjustments when tuning; observe engine response and re-check needle seating after initial runs to ensure consistent behaviour.