How The Carburetor Works

How The Carburetor Works

The carburetor is a mechanical device that mixes a certain proportion of gasoline and air under the action of the vacuum generated by the engine operation.
The gasoline enters the carburetor from the fuel tank through the gasoline filter, which can filter out the impurities mixed in the gasoline and the oxide skin in the fuel tank. If the quality of the filter is defective, some impurities still enter the carburetor through the filter. In addition, gasoline contains components that can form colloids. After long-term deposition, colloids will condense and adhere to the parts of the carburetor (such as measuring holes), oil passages and the surface of the float chamber.
The air enters the carburetor through the air filter. Based on the consideration that the intake resistance cannot be too large and other factors, the filter device cannot be too dense, so some tiny impurities in the air will still enter the carburetor through the air filter. If the filter quality is defective, it will cause more serious effects.
More components in the oil passage and air passage of the carburetor, such as the main measuring hole, the idle speed measuring hole, the main air measuring hole, the idle air measuring hole, the main foam pipe, etc. ~1.5mm), gasoline impurities, gums and impurities in the air entering the carburetor will often change or block these apertures, resulting in poor air passages and oil passages in the carburetor, making the carburetor supply Oil characteristics change, and even cause carburetor performance failure.

Carburetor normal maintenance

The normal maintenance of the carburetor is actually to maintain the cleanliness of the carburetor when it leaves the factory. This is controlled by professional carburetor manufacturers such as our company as a key indicator of carburetor quality evaluation. The company's control standards, using a variety of advanced equipment and technology to strictly control each link of production. Therefore, in order to ensure the normal use of the motorcycle, we must pay attention to the normal maintenance of the carburetor: clean the carburetor regularly, keep the oil passages and air passages of the carburetor clean, and the small apertures are unobstructed. This is also very important to prolong the service life of the carburetor. From experience, many carburetor performance failures can be solved by regularly cleaning the carburetor.
Carburetor normal maintenance precautions:
1: The carburetor is a key component in the engine, and minor changes may affect the performance of the vehicle. Therefore, during the disassembly and assembly process of the carburetor, appropriate tools should be used, and the force should be moderate to prevent deformation of the parts. The disassembled parts should be placed neatly in order to prevent missing or wrong assembly during assembly.
2: The cleaning of the carburetor should be carried out in a clean place. First wipe the outer surface of the carburetor, and use the special cleaning agent for carburetor or industrial gasoline to clean the internal parts. In addition to impurities, pay attention to cleaning the gasoline gum on the surface of the parts. The cleaned parts should be blown clean with compressed air, and cannot be wiped with cloth or paper that will produce burrs to prevent re-contamination. Blocked holes should not be opened by hard objects such as steel wires to prevent changes in the performance of the carburetor caused by changing the hole diameter. Gasoline or compressed air should be used to clean and flush out.
3: During the assembly process of the carburetor, the connecting screw of the float chamber, the connecting screw of the carburetor and the engine should not be tightened at one time, but must be tightened several times. Generally, the tightening torque is between 12N.m and 15N.m. Otherwise, the joint surface will be deformed, and air leakage or oil leakage will occur. The tightening torque of measuring hole parts is generally between 1.5N.m and 3.0N.m. Excessive tightening torque will damage the thread, cause deformation of the parts, and even produce metal chips, causing secondary pollution and affecting the performance of the carburetor.
4: In the process of cleaning the carburetor, if there is a lot of sediment in the carburetor float chamber, it is often caused by the failure of the gasoline filter. At this time, the gasoline filter should be checked, and if it is confirmed that it is invalid, it needs to be cleaned or replaced with a new gasoline filter.
5: If the motorcycle is not used for a long time, it is necessary to discharge the fuel in the carburetor float chamber to prevent the colloidal deposition of gasoline from condensing and causing the carburetor to malfunction. In addition, it should be emphasized that the position of the idle speed adjustment screw has an important influence on the performance of motorcycle emissions, idle speed, transition, and fuel consumption. When cleaning the carburetor, it is generally forbidden to move the idle air adjustment screw (see picture). If it is necessary to remove the idle air adjusting screw, screw the adjusting screw to the end first, remember the number of turns (accurate to 1/8 turn), and return according to the original number of turns during assembly.

Typical Fault Analysis and Removal of Carburetor

As a sophisticated mechanical device, the carburetor plays an important role in the engine and can be called the "heart" of the engine. From a professional point of view: the failure rate of the carburetor itself is extremely low. But why is the failure rate of carburetors often not low in actual use? There are two reasons for this: ① Since all the working characteristics of the engine are related to the carburetor, such as acceleration, transition, fuel consumption and so on. Therefore, when judging the cause of the performance failure of the motorcycle, the failure of electrical components or other mechanical parts is often confused with the carburetor, and the carburetor is mistakenly judged as a failure of the carburetor and the carburetor is replaced. For example, the failure of the filter causes impurities to block the carburetor, and the replacement of the new carburetor eliminates the fault, but does not solve the fundamental problem. ②The quality problems of related parts greatly shorten the service life of the carburetor. Such as the reduction of cleanliness, increased wear and tear of carburetor parts and so on. As a professional manufacturer of carburetors, we often encounter similar problems in our cooperation with motorcycle manufacturers. The following is an introduction to the analysis and troubleshooting of some typical faults of the carburetor.
• Difficulty starting
• Unstable idle
• poor transition
•  Lack of motivation
• Carburetor leaking oil
• high fuel consumption
The above mentioned are several common fault phenomena of motorcycles, and only the faults of the carburetor are selected for analysis. But in fact, from the perspective of the whole machine, there are many factors that cause the above-mentioned failure phenomenon. Such as difficulty in starting: the disorder of the ignition system, the change of the spark plug electrode gap, etc. will cause difficulty in starting. Such as unstable idling: In order to reduce the sound of the engine cylinder head, the motorcycle factory often adjusts the engine valve clearance too small, which leads to the deterioration of the engine intake and exhaust conditions, and the idling instability or even no idling phenomenon occurs. The user needs to analyze the fault condition of the vehicle in detail.

Get In Touch

Recommend Read