A-B1491006-AI SHAFT-THROTTLEOne New Aftermarket Replacement Throttle Shaft Fits Briggs & Fits Stratton Small Engines This aftermarket replacement throttle shaft (Fits Briggs & Fits Stratton part 491006) is a carburetor mounted component that regulates engine speed and power output by controlling the flow of air and fuel into the engine. It is also commonly referred to as a Shaft Throttle and is designed Fits Briggs & Fits Stratton (B&S) 8 12 HP small gasoline engines used in