YS Engine Throttle Stop Screw YSF1258 for RC Engines  [YSF1258]

Set physical throttle endpoints with a threaded stop

The YS Engine YSF1258 throttle stop screw acts as a replacement mechanical limiter to set idle and full-closed throttle positions on model engine linkages. It reduces the risk of throttle overtravel and gives a consistent contact point for the throttle arm.

As a threaded adjuster it replaces factory stop screws in compatible carburetor bodies or linkage mounts, providing a simple, repeatable way to control the mechanical travel of the throttle. This is a mechanical solution that works alongside any electronic throttle adjustments you may use.

Installation requires basic model engine experience: remove the original limiter, screw in the YSF1258 until it gently contacts the throttle arm at the chosen idle, then refine in small increments while testing on a bench. Avoid large adjustments while the engine is running to prevent sudden throttle movement.

Practical note: establish the mechanical stop first, then fine-tune needle settings or ignition timing for the final idle and throttle response. The stop screw simplifies setup and protects the throttle linkage during repeated use.