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

Component details and intended use

This O.S. Engine OS22781420 throttle lever fixing screw secures the throttle lever to the carburettor shaft on selected O.S. carburettor models and is aimed at model engine applications where precise lever positioning matters.

The fixing screw fits the carburettor codes 2H, 3H, 20C, 20F, 40B, 40C, and 60C. Properly fitted, it minimises play at the throttle arm pivot and helps provide consistent throttle response for more reliable tuning sessions.

Fitting is straightforward: line up the throttle lever on the shaft, pass the screw through the lever boss into the shaft thread and tighten just enough to secure the lever without over-tightening. Always recheck neutral and full-throttle travel after installation.

While not a power-upgrade, this retention screw plays a role in maintaining accurate linkage geometry which supports stable idle behaviour and predictable needle adjustments during tuning.