Analysis and troubleshooting of typical motorcycle carburetor faults

Lack of power mainly reflects the acceleration performance and high-speed performance of the motorcycle.

There are 2 indicators of motorcycle acceleration evaluation: start acceleration and beyond acceleration. Its performance indicators vary with the vehicle model and displacement, and the detection method (such as the timing of shift and the mastery of throttle opening speed) is not easy for users to master. Because different users vary greatly in the throttle control speed, the feeling of the acceleration performance is also different. Therefore, when the user feels bad acceleration, it is best to diagnose to the professional maintenance point. Users can preliminarily judge whether their motorcycle is underpowered through the following phenomena.

In the process of acceleration, obviously feel slower than before, the power decline.

The top speed drops, the high-speed vehicle "rush", the exhaust pipe has a shooting phenomenon.

The reasons of insufficient motivation and the exclusion methods are as follows:


1. Idle volume hole or main volume hole is blocked

Reason: the idle volume hole or the main volume hole blockage will cause the carburetor to dilute the oil supply, resulting in insufficient power.

Exclusion method: clean according to the above carburetor cleaning method.


2. Idle oil channel, airway, or the main oil channel, airway blockage

Reason: Idle oil channel, airway or main oil channel, airway blockage will cause the carburetor oil supply to be sparse or thicker, resulting in lack of power.

Exclusion method: Same as above.


3. The starting and thickening device works abnormally

Reason: This fault is mainly found in the bypass and thickening device. The failure of the electric bypass thickening device or the poor failure of the extension of the hairpin or the manual starting piston thickening device will lead to the failure of the starting plug, resulting in the poor operation of the hybrid engine.


Elimination method: for the carburetor equipped with the electric heating starting thickening device: the electric heating starting thickening valve should be replaced. For the vehicle with manual thickening device: it is generally due to the friction between the thickening wire and the shell after using for a long time, and the surface of the thickening wire coated with butter or other lubricating oil can be solved.


4.The acceleration pump device is not smooth or blocked (for the carburetor equipped with the acceleration pump device, such as CB125 motorcycle)

At the moment of acceleration, due to the plunger lifting speed, there will be oil supply lag, sparse phenomenon. For this reason, the acceleration pump device is set on the carburetors used in some models: at the moment of acceleration, additional oil is supplied to meet the needs of the engine and improve the responsiveness of acceleration.

Reason: accelerated pump oil channel is blocked or accelerated pump diaphragm fails.

Elimination method: plug the accelerated pump channel with compressed air to clean the accelerated pump channel; if the accelerated pump diaphragm fails, the accelerated pump diaphragm should be replaced.

Analysis and troubleshooting of typical motorcycle carburetor faults

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