YS Engine YSS9121 Throttle Barrel 91SR Replacement Part  [YSS9121]

Throttle barrel for 91SR engines

This YS Engine YSS9121 throttle barrel is an RC-scale replacement part intended for use with 91SR model engines. It serves as the core throttle slide component inside the carburetor assembly and plays a direct role in controlling airflow and throttle response during tuning and everyday operation.

Compatibility is limited to 91SR engines as indicated by the product designation. Before installation, confirm that the carburetor body and throttle linkage on your model match the physical dimensions of the existing throttle barrel to ensure proper fit and movement.

Installation notes: remove the carburetor from the model, inspect mating surfaces, and transfer the throttle slide carefully to preserve orientation. Reassemble and check that the throttle linkage moves smoothly through the full travel without binding. Small linkage or idle adjustments may be required after replacement to restore desired idle and full-throttle behaviour.

Tuning role: the throttle barrel affects idle stability and transient throttle response; replacing a worn or damaged barrel can restore consistent airflow characteristics and make fine-tuning the carburetor easier during setup. Routine inspection and light cleaning of the barrel and bore will help maintain predictable performance.