O.S. Engine OS22781420 Throttle Lever Fixing Screw for 2H,3H,20C,20F,40B,40C,60C carburettors  [OS22781420]

Throttle lever fixing screw overview

This O.S. Engine OS22781420 throttle lever fixing screw is an RC-scale carburettor component designed to secure the throttle lever on specific O.S. carburettor models. It is intended for use on model engines and serves a focused role in maintaining lever position and throttle linkage alignment during setup and track use.

Compatibility covers the listed carburettor model codes: 2H, 3H, 20C, 20F, 40B, 40C, and 60C. When the fixing screw is correctly installed it prevents unwanted play at the throttle arm pivot, which contributes to repeatable throttle response and more consistent tuning outcomes.

Installation is straightforward: align the throttle lever to the carburettor shaft, insert the fixing screw through the lever boss into the shaft thread, and secure without excessive force to avoid stripping threads. Check lever travel after securing and confirm neutral and full-throttle positions before running the engine.

From a tuning perspective this part is a maintenance item rather than a performance upgrade; ensuring the fixing screw is correctly fitted reduces slop in linkage geometry which helps maintain idle stability and predictable throttle progression during needle and high-speed adjustments.