YS Engine YSS5121 Throttle Barrel Spare for RC Maintenance  [YSS5121]

Throttle sleeve for model engines

This part serves as an RC-scale throttle sleeve intended for installation inside a carburettor or throttle housing on model engines. It is the rotating component that meters airflow and translates control input into throttle position on compatible setups.

The write-up stresses correct fitment rather than universal application; confirm the part number and dimensions with your vendor or engine documentation prior to fitting. Installation commonly requires removing the carburettor housing, seating the barrel squarely in the bore, and ensuring it turns smoothly across the throttle travel. Observe lubrication and clearance practices recommended by your engine maker.

In tuning terms, changes to the barrel affect idle stability and throttle response by altering airflow geometry, so verify linkage alignment and return spring operation after replacement. Check for wear where the barrel contacts the carburettor bore and renew the part if you find scoring or excessive play.