What Causes a Carburetor to Leak Fuel?
2 Answers
Carburetor fuel leakage can be caused by: 1. Excessive fuel level; 2. Sticking of the needle valve or float, or clogged return fuel line; 3. Poor sealing of the venturi; 4. Excessive fuel pump pressure. The carburetor is a mechanical device that mixes a specific ratio of gasoline with air under the vacuum created by the engine's operation. As a precision mechanical device, the carburetor utilizes the kinetic energy of the incoming airflow to atomize the gasoline. The carburetor's crucial role in the engine can be likened to the heart of the engine, and its complete assembly should include a starting device, idle device, medium load device, full load device, and acceleration device.
Last time my old car had the same issue, a leaking carburetor looked scary, but there are usually just three or four common causes. Mainly, the needle valve in the float chamber gets stuck or the sealing gasket is damaged, causing gasoline to seep out through the gaps. Another reason is aging fuel lines cracking; rubber hoses become brittle after over a decade of use and may spray fuel when pressurized. If the float gets stuck by sludge, the fuel level rises too high and overflows. Installation issues like loose carburetor base screws are also quite common. Once, my car had the carburetor backfiring because it was overfilled, causing poor fuel return. It’s crucial to clean up gasoline spills immediately—gasoline dripping on the exhaust pipe can ignite. Pushing it straight to the repair shop is the easiest solution.
