The first type can be compared. After replacing the new ignition coil, the fault is eliminated and the engine is working normally, indicating that the ignition coil is damaged.

Secondly, the resistance of the low-voltage coil and the high-voltage coil of the ignition coil is respectively measured by a multimeter. The value of the low-voltage coil is about 1 ohm, and the value of the high-voltage coil is about 5,000 ohms, which is normal. If the resistance value is too small, it may indicate a short circuit inside the ignition coil; if the coil is not connected, the ignition coil is open.

The third type is to check with 220 volt AC. Connect the 25 watt bulb in series with the 220 volt circuit as a test light. Use two insulated contact pins to contact the positive and negative terminals of the low voltage coil of the ignition coil. , indicating that the low voltage coil is good; if the test light is not bright, it is an open circuit.