How to Clean a Motorcycle Carburettor
It’s fundamental to clean a motorcycle’s carburettor after a certain number of kilometres or if its operation isn’t fluid. A motorcycle’s carburettor is its nerve centre in which everything revolves around. It is a very sophisticated component consisting of many parts that have different and essential functions. Some of these parts can be variously adjusted to change the air/petrol ratio or to run the engine cold, at maximum, at minimum, etc. It’s important to note that each motorcycle manufacturer installs different types of carburettors on its different models.
Carburettors can also be very different from each other, even if they share the same operating principle. Regardless, motorcycle owners must carry out routine maintenance and cleaning on the carburettor, without causing problems such as the calibration of jets and air intakes or the incorrect adjustment of the minimum, maximum etc. For these reasons, before proceeding with (ordinary or extraordinary) motorcycle carburettor maintenance, it’s essential to refer to the manual of the motorcycle and carburettor.
Things you will need
Screwdriver
Thin-nose pliers
Compressed air
Steel wire
Step 1
Before disassembling the carburettor
Depending on the shape of the motorcycle body, in most cases you will need to disassemble the protective casing to reach, and properly work on, the carburettor. Before you start the operation, carefully wash the motorbike to avoid mud, sand and asphalt residues from ending up inside the carburettor and subsequently causing serious damage. Once cleaned, you must thoroughly dry the bike. Once completely dry, apply a generous spray of on the carburettor to eliminate any stubborn residues and facilitate disassembly.
Step 2
Disconnecting the air filter
The carburettor is connected to the piston head, air filter, throttle/air tie rod and petrol tube coming from the tank. To clean the motorcycle’s carburettor, you need to remove the air filter by loosening the screws (or other systems). This filter (in various shapes and structures) must be carefully evaluated: some can be washed or cleaned by blowing, others not, and if they are clogged they must be replaced.
Step 3
Disconnecting the petrol tube and the tie rod
The petrol tube is securely connected to the carburettor by a metal or plastic clip. After closing the feed valve exiting the tank, use the pliers to press the tabs of the clips, then remove the tube from the carburettor. The cable coming from the throttle knob and (if present) the automatic air regulation system must also be disconnected from the carburettor head. The petrol inlet into the carburettor is often fitted with a small fuel filter that must be examined and cleaned too.
Step 4
Extracting the carburettor
The carburettor is connected to the engine with various systems. The most common is a short sleeve of synthetic material or rubber inserted at the carburettor outlet and connected to the mouth of the engine head where it is fixed with a metal band. Loosening this can disconnect the carburettor. In some cases, it is fixed to the cylinder head with studs. If there are studs, a few sprays of WD-40 Multi-Use will help you loosen them quickly and effectively. The carburettor can now be extracted from its seat.
Step 5
Checking the gaskets and opening the tray
The first thing to check is the condition of the gaskets: the one for connection with the cylinder and the one (if any) interposed between the carburettor and the air filter. The integrity and functionality of both are very important because tears, swelling or breakage cause malfunctions or can even stop the engine. Then, remove the petrol tank by unscrewing the lower central screw that fixes it (make sure you work over a container). The bottom of the tray is often dirty with deposits and encrusted material. Now clearly visible, the float can be separated by removing the small steel axis on which it pivots and also removing the pin connected to the float. Also, check the gasket of the tray as this often needs to be replaced. Place everything in a container and spray abundantly with WD-40 Multi-Use, which will optimally penetrate and clean the various components thanks to its unique and fast-acting formula.
Step 6
Cleaning the internal components of the motorcycle's carburettor
The carburettor has mixture sprayers, adjustable minimum and air jets, and the guillotine with the pin. If you don’t have specific skills to do this, simply leave them in place and blow compressed air into the holes. If you are more experienced, to clean the carburettor, you can always disassemble and clean it with the same product by passing a steel wire through its holes, being careful not to bore them. The carburettor body can then be immersed in WD-40 Multi-Use (also available in tanks).
Step 7
Reassembling and lubricating the tie rod
Once the carburettor is perfectly clean, thoroughly dry and reassembled, place each component in its place and then put it in position by performing the above operations backwards. Also pay attention to the connections of the drive rod, which must be treated with a spray of WD-40 Specialist PTFE Dry Lubricant.
Clean and ready to go
From cleaning the carburettor to lubricating the brakes, there is a lot that goes into maintaining your motorcycle. So make sure you read our guides and, more importantly, always have WD-40 on hand!
The uses shown and described for WD-40 Multi-Use Product were provided to WD-40 Company by the users themselves. These uses haven’t been tested by WD-40 Company and do not constitute a recommendation of suggestion for use by WD-40 Company. Common sense should be exercised whenever using WD-40 Company products. Always follow the instructions and take heed of any warnings printed on the packaging.
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