Why is the motorcycle emitting black smoke with insufficient power?
1 Answers
Reasons for a motorcycle emitting black smoke with insufficient power: The mixture is too rich due to various reasons, such as a clogged air filter, an overly rich carburetor mixture ratio, improper use of the choke, excessively high fuel level, incorrect needle position, oversized main jet, issues with the main jet and emulsion tube, or poor carburetor quality. Below are the solutions for a motorcycle emitting black smoke with insufficient power: 1. Replace with a slightly smaller idle jet. 2. Adjust the float height and observe the fuel level in the float chamber—it should be at 2/5 of the chamber for a normal level (Note: When observing the fuel level by removing the lower cover, ensure the carburetor is upright to prevent fuel spillage, which could lead to inaccurate fuel level judgment). 3. There are three types of enrichment valves: manual plunger-type enrichment valve, vacuum diaphragm plunger-type enrichment valve, and electric heating plunger-type enrichment valve. The manual plunger-type enrichment valve is relatively simple to repair—cleaning the plunger, replacing the spring, or adjusting the cable can resolve reset issues. For the vacuum diaphragm plunger-type enrichment valve, mainly check if the vacuum tube or diaphragm is cracked or leaking. The electric heating plunger-type enrichment valve usually has issues with damaged heating elements or faulty power supply circuits; damaged heating elements must be replaced.
