A small engine carburetor is one of the most important small engine parts. It mixes fuel and air together. This mixture is necessary for the engine to function. Carburetors, especially those found on small engines, are relatively simple devices, but they do require periodic maintenance to ensure they function properly.
Causes of Carburetor Problems
The biggest cause of carburetor problems is a result of fuel evaporating in the carburetor. Over time this leads to a gum-like substance preventing the carburetor from operating properly or at all. The most common problem occurs when the needle becomes stuck and the fuel is no longer able to flow. Problems can also occur if dirt or debris gets into the carburetor through the air intake.
Remove gas from the carburetor. This is especially important if the engine will be sitting for a while. To remove gas from the carburetor simply turn off the fuel line valve and allow the engine to keep running until it dies naturally. By doing this you are allowing the engine to burn the fuel remaining in the carburetor. It is also a good idea, especially for long periods of storage, to remove all fuel from the fuel tank.
Replace the air filter regularly. Every time you change the oil you should inspect the air filter. If it looks dirty and worn, replace it with a new filter. This not only ensures better operation of the engine but it helps prevent particles of dirt and other debris from getting into the carburetor. Never run the engine without an air filter.
10 Steps for Cleaning a Dirty Carburetor
Step 1 - Turn off the Fuel Valve
Step 2 - Remove Carburetor
Remove the carburetor completely from the engine. The steps to do this vary depending on the engine design and model, but typically you need to remove the air filter panel and disconnect the governor and fuel line from the carburetor.
Step 3 - Open the Carburetor up
Most small engine carburetors have a nut or a screw at the bottom of the carburetor bowl. Holding the carburetor over a bucket, remove the screw and take the bowl off. Allow the left over fuel to drain into the bucket.
Step 4 - Observe
Pay close attention to the layout of the interior of the carburetor.
Step 5 - Check the Needle
Inspect the needle to determine if it is stuck or sticking. The needle should move easily and smoothly. The needle is a small bullet-shaped device. It is made out of plastic, although it may also have some aluminum covering it.
Step 6 - Clean the Needle
If the needle appears to be stuck it needs to be cleaned. Remove it and clean it using a wire brush and either carburetor cleaner or brake cleaner. Replace it and test it.
Step 7 - Clean
Spray carburetor cleaner or brake cleaner into all the fuel lines throughout the carburetor. Inspect them for any buildup that may block proper flow.
Step 8 - Test the System
If you have a carburetor test, use it to test the carburetor.
Step 9 - Reassemble
Reassemble the carburetor and attach it to the engine.
Step 10 - Test the Results
Test the engine to determine if it is functioning properly. Remember, the carburetor will be fully drained so it may take several seconds for the bowl to fill up with fuel.
That's all there is to it! These cleaning and maintenance tips will keep your small engine carburetor running smoothly.