(6) Troubleshooting of abnormal work of neutral indicator light

Fault phenomenon: motorcycle electrical line fault, in the ignition switch is not opened, if continuously step the start rod, the neutral indicator will light up, if open the ignition switch for inspection. The neutral indicator is still working properly.

Fault analysis and troubleshooting: Continuously step on the starting rod for inspection to confirm that the electrical line is not working normally. According to the fault phenomenon and the working principle of the whole vehicle electrical system, without starting the ignition switch, continuously step on the starting rod, and the neutral indicator lights up, which is abnormal, indicating that the direct current output of the charging system is not transmitted through the ignition switch into the electrical equipment line, so that the neutral indicator lights up. And the charging system and battery output direct current under normal circumstances, only through the ignition switch to the whole vehicle electric equipment power supply, so continuous step start rod, neutral indicator light on the light shows that the electrical line is not working normally.

Based on the schematic diagram of the motorcycle charging system, it is found that the charging system of this type of motorcycle has been greatly improved. The charging system uses single-phase permanent magnet alternator and new full-wave voltage stabilizer. The full-wave stabilized rectifier has the function of the five-terminal full-wave stabilized rectifier, although it has only four wiring strips like the ordinary 70 motorcycle stabilized rectifier. According to this analysis, it is likely that the maintenance personnel do not know the function and use characteristics of the new full-wave voltage stabilizer, and the line connection error occurred during the maintenance, leading to the abnormal work of the electrical line. Two of the four terminals of the new stabilized rectifier are AC input terminals, one is DC output terminals, and the other is DC voltage sampling terminals. The metal housing of the full-wave stabilized rectifier is the ground terminal.

(7) Failure cause that can not be started after flameout

Failure phenomenon: a two-stroke pedal motorcycle, traveling about 2500km, at the end of a long journey, the engine self-flameout after can not start.

Fault analysis and troubleshooting: test start engine, engine can not start. No high voltage spark was found in the fire jumping test at the end of the high voltage wire, indicating that the ignition system was faulty. Unplug the connection between the ignition switch and the body circuit. That is to cut off the ignition system to the ignition switch short circuit type flameout line, and then high voltage wire end fire jumping test, still no high voltage spark, indicating that the ignition switch and short circuit type flameout line is good. Unplug the connection plug of igniter and ignition coil, take a large light bulb as a test lamp, connect a wire at each end of the bulb, connect a wire to the body, and connect the other wire to the ignition current output line of the igniter, step on the starting lever to turn the crankshaft, test lamp continuously shining. It indicates that the ignition current output of the igniter is good and the ignition coil is faulty. By measuring the ignition coil with a multimeter, it is found that the primary coil of the ignition coil is disconnected. Because the primary coil of the ignition coil is disconnected, the ignition coil can not generate high voltage, resulting in the engine can not start. Replace the good ignition coil, reinstall the removed parts. High voltage wire end spark good, easy engine start, work well, troubleshooting.

(8) Sudden weakness during driving

Reason analysis: vehicle power shortage, involving many factors. The piston and piston ring should be fine for a car with a conventional driving distance of only 2,000km, and the owner of the car said that it should operate strictly according to the regulations of the run-in period. In response to the user's repeated requests, replacement work. During the replacement process, I talked with the user and learned that 1 liter of oil had been added to the gear transmission before the fault occurred. So far, finally understand the cause of the failure.

The car transmission gear transmission filling standard should be 450ml gear oil, and the user in 450ml gear oil on the basis of mixed with 900ml oil, so that the transmission box internal operation resistance, power consumption.

Elimination method: all the mixed oil in the transmission gear transmission is released, cleaned with gasoline, and re-loaded with 450ml gear oil. Start engine test, power performance and acceleration performance return to normal, the fault is eliminated.

(9) The fault phenomenon of one rush and one meal when the vehicle is running

Fault phenomenon: a curved beam type motorcycle, driving a rush a meal phenomenon, and speed up difficult.

Fault analysis and elimination: according to the fault phenomenon, it is believed that the cause of this fault is mainly the oil supply system or ignition system problems, so that the engine can not operate normally.

Firstly, the motorcycle oil circuit was checked and the carburetor was removed and washed, but the problem was not solved. Then check the valve clearance of the engine, valve timing, and so on, did not find the problem. Replace the spark plug, the fault is still not removed. Pull the high voltage wire from the spark plug high voltage cap, close to the engine housing for fire jumping test, the spark is strong, then check the high voltage cap, found that its internal damping resistance burned out, replace a new high voltage cap, troubleshooting.

(10) Driving weak, exhaust pipe black smoke

Fault phenomenon: driving weak, exhaust pipe smoke.

Fault analysis and elimination: first remove the air filter, start the engine, the fault phenomenon is still the same, clean the carburetor, check the automatic concentration valve working normally, install the retest car fault phenomenon is not improved, check the compression pressure, found very small, after releasing the water, remove the cylinder head, check that the piston ring serious wear, valve serious leakage, replace the piston ring, repair the reclining valve, loading trial,

The engine starts easily and the black smoke disappears, but when the engine turns off, there is a stir in the engine and it starts again.

Listen carefully to the sound from the generator side. Remove the water pipe, oil pipe, open the side cover. When removing the rotor nut, it is found that the nut fastening force is not enough. At the same time, the big gear beyond the clutch is also stuck, forcing down the big gear, may be the support has turned over, causing the big gear beyond the clutch stuck, analysis that because of the replacement of a new ring and eliminate the valve leakage fault, the engine compression force increases, causing the crankshaft connecting rod to withstand the gas explosive force is larger than before the failure, so that the original damaged key is cut off, remove the crankshaft, A new keyway was milled on the opposite side of the original keyway of the rotor and crankshaft, and the heavy car was assembled with a semicircle key. The owner was very satisfied after the test ride.

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