Cleaning a carburetor correctly is essential. Think of the carburetor as the heart of any motorcycle. If it is clogged, the bike is going to spit and sputter and run horribly. The passageways through the carburetor can easily be clogged up with dirt and debris. This dirt and debris can be sucked in through the air filtration system on your bike, or can find its way through the fuel system, such as, a rusty/dirty gas tank.
To prevent dirt or debris from entering your carburetor it is very important to maintain a clean air filter and gas tank. This means cleaning and re-oiling your air filter after long rides. In addition you will need to ensure that rust is not forming in your gas tank, and that you have a clean fuel filter on at all times. These are simple maintenance tasks that anyone can do.
To properly clean a carburetor you are going to need a few tools:
The first step to cleaning a carburetor is getting it off of the bike that it is currently attached to. If your bike is bogging or breaking up, this could mean you need a carburetor clean. Simply start by unscrewing the two clamps around the intake manifold and air filter housing on your bike.
Remove the carburetor body and detach the throttle cable and slide from the carburetor. You will be left with the carburetor body.
Once you have removed the carburetor body, start taking off the float bowl on the carburetor. The float bowl is the underpart of the carburetor where gas pools and gets pushed up into the carburetor. Usually the float bowl is held on by four small crews.
Once the float bowl is removed, you will have access to the inside of the carburetor. Check to see if there is any visible debris floating or stuck to the inside of the float bowl. This is a common place for rust and dirt to settle. Take your carburetor cleaner and spray the visible debris out of the carburetor.
Once the float bowl is cleaned, move onto the top portion of the carburetor. This portion of the carburetor is where you can find the jets. Usually there are two small jets called the main jet and pilot jet or idler jet. If your bike does not idle, your pilot jet is most likely clogged. If your bike bogs and has poor throttle response, your main jet could be clogged. Simply remove these two jets either the wrench or the screwdriver of choice.
Inspect the jets for clogged holes and passageways. Oftentimes holding the jet up to the sun will help you see if it is clogged or not. Sometimes the jets can be covered by the float. The float is what turns and shuts off the fuel flow in the carburetor. The float is often held on by a small pin that slides through the float into the carburetor. Remove this and take off the float.
Under the float you will find the needle. This is what physically shuts off the fuel flow on the carburetor. If your carburetor is constantly leaking you could have a faulty needle. The tip of the needles on carburetors are sometimes covered in rubber. This rubber can harden over time and cause the carburetor to leak.
Once the needle and float are removed from the carburetor look for a hidden screw called the air/fuel screw. This screw controls how much fuel and air are allowed into the carburetor. It is very important for keeping a constant and consistent idle. Remove this screw and the spring behind it.
After every jet and screw is removed from the carburetor, take your carburetor cleaner (you can buy this at any hardware automotive store), and spray through each passageway for the carburetor. You can also buy an ultrasonic cleaner for this step, and just put the whole carburetor right in the ultrasonic cleaner. It will clean the whole carburetor for you. Ultrasonic Cleaners cost around $100. If you do not have access to an ultrasonic cleaner, continue spraying the carburetor cleaner into the passageways until they are unclogged. Take your wire brush, and make sure each of the holes in the jets are unclogged.
After each jet is cleaned and each passageway on the carburetor is cleaned, take your air compressor and blow through all of the passageways and holes in the carburetor to get any last standing debris out of the way.
Your carburetor is now clean.
Reinstall the jets, the needle, the float, and the air screw. Put the carburetor back into your bike. Your bike should now run at optimal performance.