High-speed black smoke

Symptoms for more than four or five thousand rpm the exhaust pipe smoke clear, vehicle speed power is clearly insufficient. Fault: (1) air filter or clogged air intake passage; (2) main jet cross-sectional area is too large; (3) the main nozzle hole and needle with too much space; (4) the oil level is too high. Solution: (1) clean or replace the air filter paper Filter; (2) replacement of small cross-sectional electric scooter motor area of the main jet. Here to talk about the disassembly and adjustment of the carburetor. First remove the carburetor and air filter, clean or replace the filter filter, open the carburetor main jet cleaning inspection, pilot jet, the amount of air holes, adjust the float chamber oil level to normal, the oil needle transferred last card of a cell, and then refitted the carburetor and air filter, start the vehicle, the car preheat 2min-3min, plunger height adjustment screw to adjust the idle speed minimum, and then adjust the idle air screw to adjust the engine speed up , and then to adjust the idle speed adjustmentelectric motorcycle scooter screw plunger minimum, and then adjust the idle air adjusting screw to speed up, repeatedly adjusted several times, until the lowest position of the plunger, and the engine speed up and running smoothly, that is adjusted to the optimum position. Slow fuel door, the engine speed should be smooth rise, the throttle should be no sense in any block opening, otherwise the needle to remove the card downward adjustments until satisfied.