Idle black smoke

Failure phenomenon: When idling vehicle exhaust pipe smoke clear, exhaust sound dull (sometimes wonder muffler damage), we must increase the throttle to start to start. Reasons for failure are: (a) pilot jet is too large; (2) float chamber oil is too high; (3) Start motorcycle engine parts enriched valve is not closed; (4) with the gap needle and main jet hole is too large. Here is the solution: (1) replacing the smaller pilot jet. (2) adjust the float height, observed two-fifths of the oil level is normal oil level float chamber to the float chamber (note, open the lid when viewed under the oil level, the carburetor must be upright, to prevent the gasoline spread out, causing the oil level is not accurate judgment). (3) There are three start-enriched valve forms: manual plunger enriched valve, vacuum diaphragm plunger enriched valve, electric valve plunger enriched. Manual plunger valve repair enriched relatively simple, clean plunger through replacement return spring or cable solve the motorcycle engine types problem. Vacuum diaphragm check valve is mainly concentrated column Saiga vacuum, vacuum diaphragm rupture, leak. Electric plunger valve is usually enriched electrical heating element damage and power line failures, electrical heating element is damaged and must be replaced. (4) Oil needle and main jet holes with the gap is too large to be replaced standards for new accessories.