Why Does a Motorcycle Emit Black Smoke at High Speed?
1 Answers
There are two scenarios when a motorcycle emits black smoke at high speed: the first is idling with black smoke, and the second is emitting black smoke at high speed. Possible causes of the fault include: Excessively large idle jet; excessively high fuel level in the float chamber; the starting enrichment valve (choke) not being closed; excessive clearance between the needle jet and the main jet. Fault resolution methods: Replace with a slightly smaller idle jet, adjust the height of the float, observe the fuel level in the float chamber to reach 2/5 of the float chamber as the normal fuel level. There are three types of motorcycle starting enrichment valves: manual plunger-type enrichment valve, vacuum diaphragm plunger-type enrichment valve, and electric heating plunger-type enrichment valve.