A-B1691931-AI SHAFT-THROTTLEOne New Aftermarket Replacement Throttle Shaft Fits Briggs & Fits Stratton Small Engines This carburetor throttle shaft (part number 691931) is a key component of the carburetor assembly in Fits Briggs & Fits Stratton small engines. The throttle shaft controls the throttle plate, regulating airflow into the engine and enabling accurate engine speed control. A worn or damaged throttle shaft can cause rough idling, poor throttle response, and reduced