YS 120SR Throttle Barrel Upgrade - YSS3021 Throttle Barrel Replacement for RC  [YSS3021]

Durability and Function of the Throttle Barrel

This YS Engine YSS3021 throttle barrel is a replacement component for the YS Engine 120SR family. It functions as the mechanical interface between the carburettor shaft and throttle linkage, providing direct control of throttle movement on small model engines.

The barrel's function is mechanical stability: ensure free rotation, correct linkage alignment, and repeatable throttle travel. Inspect the bore and mating surfaces for any scoring or looseness when replacing the part, and confirm the throttle snaps back to idle without any binding throughout the travel.

Fit the barrel squarely in the carburettor housing and verify the throttle arm lines up with the linkage. Minor tweaks to linkage geometry or the throttle stop positions may be necessary to recover factory idle and maximum opening points; always move the throttle through its full travel during setup. Regular checks during maintenance will extend service life and preserve consistent response.