There is a straddle ride motorcycle, has been running 53,000 kilometers, the owner said a period of time ago for routine maintenance, after the change of lubricating oil strange things happened, the engine is difficult to start, barely started, on the road occasionally broken fire phenomenon.

Also let other maintenance workers check, replace spark plug and pressure pack, are invalid. With the passage of time, the fault became more and more serious, the specific performance of the engine is difficult to start, easy to stall on the way, the cause of the fault is unknown.

On the surface, this fault should be caused by abnormal electrical system, and there are many causes: spark plug, high voltage, electronic igniter (that is, C.D.I), magneto excitation coil and fixed, rotor, ignition switch and electrical system wiring, connector failure, are likely to cause the fault.

Section by section by electrical system. Turn on the ignition switch, remove the spark plug from the cylinder in the order of replacing the C.D.I and the FBT, put it on the high-pressure damping cap, and test the fire near the cylinder head. The failure is still the same.

Observe the appearance of the connection wires and connectors of the above mentioned electrical components, and there is no loose, exposed or broken phenomenon. Dial the universal ammeter to the ohm stop, check whether the circuit system has short circuit, virtual connection phenomenon, so that the fault range is gradually reduced to the magneto part.

Find a car with a light bulb, the two poles are connected to the magneto lead out line as a test lamp, one end is connected to the ignition power coil output end, the other end in the body of iron, tap the start lever, the test lamp flashing light, indicating that the ignition power coil work well.

Open the left crankcase cover and check the excitation coil connection line on the stator. There is no abnormal phenomenon. Use multimeter (Ω (1) two pens and left and right, respectively, trigger coil lead wire cylinder measurement, namely, yellow/white with blue/yellow line on both ends of the resistance, the left and right cylinder trigger resistance between 120 ~ 146 Ω, belongs to the normal state.

Careful observation of the green/white line of the trigger coil shows that the riveting point of the ground wire end is loose. In order to verify the fault, the pen of the grounding wire is connected to the riveting point, the pen of the original output end is not moving, gently pull the ground wire, the measuring needle appears large swing.

From this judgment, the fault arises from here. Replace the trigger coil, connect the end of the high voltage cable to carry out the spark test, the result is continuous and strong. Connect all the wiring harness of the electrical system, start the vehicle very smoothly, ride on the road for about 10 kilometers, the motorcycle runs normally, confirm the original vehicle troubleshooting.