How to Clean a Car Carburetor?
4 Answers
Methods for cleaning a car carburetor: 1. Remove the air filter, start the engine, and let it reach maximum RPM; 2. Use your palm (you can wear clean gloves or use a clean cloth) to quickly cover the carburetor's intake port. At this point, you should feel a strong suction force, and the engine RPM will gradually decrease. When the RPM is relatively low, quickly remove your palm to allow the engine to return to normal operation; 3. Repeat steps 1 and 2 as needed until the engine operates normally. If you have carburetor cleaner available, using it in conjunction with these steps can enhance the cleaning effect and reduce the number of repetitions required.
That day I cleaned the carburetor of my old Santana, which required extra attention. First, I removed the air filter and fuel lines, then sprayed carburetor cleaner aggressively onto the main body and venturi. Watching the years of sludge dissolve and drip down was oddly satisfying. I carefully cleared the jets with copper wire, being careful not to enlarge the holes, or fuel consumption would increase. Before reassembly, I made sure to blow out every air passage with compressed air. Adjusting the mixture screw took me half an hour—turning it clockwise all the way and then backing it off two and a half turns proved to be the ideal starting point. After completion, starting the engine showed much more stable RPMs, though it's best to check the fuel filter condition while working on an old car.
During my internship at the repair shop, I observed mechanics handling many clogged carburetors. The key is to remove the entire carburetor assembly, disassemble it, and soak small parts in specialized cleaner for half an hour. Focus on cleaning the main jet and idle circuit, using a 0.3mm probe for safest unclogging. The fuel valve spring in the float chamber tends to stick, requiring repeated pressing to test rebound. During reassembly, the gasket must be replaced - we always keep universal repair kits on hand. After installation, tailpipe gas analysis is needed to adjust CO levels between 0.5% to 1.2% for compliance, a step difficult to perform properly at home.
Cleaning a carburetor isn't actually difficult, I do it often myself. Get a can of NX5000 cleaner from Daihatsu Kogyosai, the kind with a fine nozzle tube. After removing the carburetor, scrape off the carbon deposits from the choke shaft and throttle shaft. The jets should be clear enough to see light through them when held up. For the float needle valve, I recommend scrubbing with a toothbrush dipped in gasoline - never spray carburetor cleaner directly on rubber components. The most commonly overlooked part is the accelerator pump diaphragm, which needs replacement if aged. Remember to wear rubber gloves and goggles throughout - that cleaner stings like hell if it touches your skin. If the idle is unstable afterward, check for vacuum leaks at the intake manifold gasket.
