What Causes No Electricity in Motorcycle Spark Plug Wires?
2 Answers
Motorcycle spark plugs have no electricity due to a malfunction in the ignition system. Motorcycle spark plug power supply principle: The 15KV voltage on the motorcycle spark plug is generated by a dedicated high-voltage circuit. Inspection methods: Check if the motorcycle battery has power or voltage but no current output. The motorcycle battery supplies power to the self-excited oscillation circuit for ignition, which converts it into the low-voltage pulse required by the low-voltage coil of the subsequent high-voltage coil. If the battery has no power, it cannot generate the low-voltage pulse, preventing the high-voltage coil winding from producing a high-voltage pulse, resulting in no voltage on the spark plug and thus no ignition. An old battery may show voltage but fail to output current when in operation. Solution: Replace with a new battery for inspection. If the power supply wire from the motorcycle battery to the self-excited oscillation circuit is disconnected or has poor contact, the self-excited oscillation circuit cannot generate the low-voltage pulse required by the low-voltage coil of the high-voltage coil. This prevents the high-voltage coil winding from producing a high-voltage pulse, leading to no voltage on the spark plug and thus no ignition. Solution: Carefully inspect for broken copper traces, poor solder joints, or other circuit disconnections. If the transistor or oscillation module in the self-excited oscillation circuit is damaged, or the inverter capacitor is faulty, no low-voltage pulse is generated. This prevents the high-voltage coil winding from producing a high-voltage pulse, resulting in no voltage on the spark plug and thus no ignition. Solution: Remove the transistor and check for damage using a multimeter. Measure the capacitor's capacity with the multimeter's capacitance setting to see if it has changed. If there is a disconnection in the self-excited oscillation circuit, its power supply, the low-voltage winding of the high-voltage coil, or the high-voltage winding, the high-voltage coil winding cannot produce a high-voltage pulse, leading to no voltage on the spark plug and thus no ignition. Solution: Carefully inspect the connection lines and copper traces for breaks or poor solder joints.
I remember my motorcycle had a problem with the spark plug wire not delivering electricity a few days ago, and it took me a whole day to finally fix it. Possible causes include the spark plug wire aging, cracking, or breaking—if the internal copper wire is broken, it can't conduct current. Additionally, the ignition coil might be burnt out, leading to insufficient current generation. Another possibility is a blown fuse, like that time when water splashed on my bike in the rain, causing a short circuit and melting the fuse. Also, check if the terminal connections are loose or corroded, leading to poor contact—a loose connector was one of the issues in my case. By the way, this problem can cause the engine to fail to start or misfire, affecting riding performance. I suggest first unplugging the connector to check for corrosion, trying a new fuse, and if that doesn’t work, quickly take it to a professional shop to avoid any accidents.
