Adjust the air/fuel ratio: The engine's carburetor ensures the engine runs smoothly by injecting the correct air ratio. To 43cc 49cc 52cc 15mm Carburetor Kit Carburetor with Gasket Pipe Spark Plug Fuel Filter Replacement Parts Carburetor. For More Effects: The carburetor also has the function of atomizing the fuel to make the machine run normally. The carburetor is designed to provide better throttle response and overall engine performance, making it an ideal upgrade for performance motorcycle engines. The carburetor's mixture ratio can increase or decrease engine power and fuel efficiency.