YS Engine YSS7121 Throttle Barrel 61ST-H spare part  [YSS7121]

Throttle barrel for RC carburetors

The YS Engine YSS7121 throttle barrel is an RC-scale replacement part intended for use within YS Engine carburetor assemblies. As a direct-change barrel component, it serves the throttle slide bore and throttle plate interface and is described here in neutral, technical terms for hobby workshop use.

This barrel is made with an aluminum-style construction aimed at maintaining a stable bore and smooth throttle movement. When replacing a worn or damaged barrel, remove the carburetor from the model, inspect the throttle slide and linkage for wear, fit the new barrel to the carburetor body, and verify free movement across the throttle throw before reinstalling on the engine. Always confirm the part number against your carburetor casting before ordering.

In tuning and maintenance workflows the throttle barrel contributes to consistent throttle response and idle behaviour by preserving bore shape and reducing irregular airflow at partial throttle. Use this spare as part of routine maintenance or when restoring reliable throttle actuation on glow-engine RC models.