91SR Throttle Barrel YSS9121 for YS Engine  [YSS9121]

Throttle barrel specifics for 91SR engines

The YS Engine YSS9121 throttle barrel serves as the replacement throttle slide designed specifically for 91SR model engines. As the moving element in the carburetor, it governs airflow and has a direct influence on how the engine responds to throttle inputs.

Compatibility note: this component targets 91SR installations. Before attempting fitment, compare the barrel profile and linkage geometry on your model to the original part to confirm correct fit and free movement.

Installation guidance: detach the carburetor from the airframe, inspect mating faces, and carefully move the throttle slide while keeping its orientation. Refit the carburetor and verify the throttle linkage travels fully and without catching. Minor idle or linkage tweaks may be required to dial in performance after the change.

Tuning impact: swapping a worn or damaged barrel can restore predictable airflow characteristics, improving idle stability and transient response and making fine carburetor adjustments easier. Periodic cleaning of the bore and slide preserves consistent results.