Idle screw
From MopedWiki
An"idle screw' is a screw found near the throttle on a carburetor which limits how much the throttle can close so as to maintain a desired idle speed when the throttle is released.
An"idle screw' is a screw found near the throttle on a carburetor which limits how much the throttle can close so as to maintain a desired idle speed when the throttle is released.