How to Measure the Quality of a Motorcycle Igniter?
4 Answers
First, remove the spark plug for inspection. Under normal conditions, the spark plug gap should be between 0.5 to 0.7mm. You can use the thickness of a small hacksaw blade to check the gap; it should feel slightly stuck when inserted. Below is relevant information about the igniter: 1. Components: The igniter mainly consists of a power source, ignition coil, distributor, ignition switch, spark plug, additional resistor and its short-circuit device, high and low voltage wires, etc. 2. Identification Method: When all the wiring of the igniter is connected, do not connect the power line (the charging end of the AC igniter) first, or disconnect the high-voltage output wire of the magneto in advance. After ensuring the ground wire of the igniter is well connected to the vehicle's circuit ground, remove the high-voltage cap from the spark plug and insert a spare spark plug connected to the vehicle body. Finally, connect the charging end of the igniter to the motorcycle's DC circuit (the positive wire connected to the battery's positive terminal).
When I first started riding motorcycles, I also encountered ignition coil issues. Measuring whether an ignition coil is good or bad is actually not difficult, the key is to use a simple multimeter to test the resistance. First, unplug the ignition coil and disconnect all connections, then set the multimeter to the resistance mode and insert the probes into the ignition coil's pins. A good ignition coil's resistance is usually within a specific range, like between 0.5 to 1 ohm. From my experience, if the reading is 0, it means there's a short circuit; if it shows infinity, it's broken. If you don't have a multimeter, you can reconnect it to the battery and test for a spark—install an old spark plug, turn the ignition key, and see if there's a blue spark. If it's dim red or doesn't spark, the ignition coil is definitely faulty. I suggest not messing around with it—safety first, because a faulty one can misfire. Finally, a reminder: if the ignition coil is broken, the bike won't start, so don't force it—just take it for repair or buy a replacement part and swap it yourself.
In the motorcycle repair industry, I've worked for many years, and testing the ignition coil's condition is a routine task. The method is quite professional: first, use a diagnostic tool or an old-fashioned multimeter to check the resistance value and voltage fluctuations. For a CDI ignition coil, a resistance of 0.3 ohms is normal, while a PEI type might be slightly higher. If there's no spark, simply unplug the ignition coil connector and test the continuity between terminals—continuity indicates a short circuit, while no continuity means an open circuit. You can also observe the voltage changes during startup; a healthy ignition coil will show a spike of 10-15 volts. I often use a spark tester for a quick verification: connect it to the battery, press the start button, and if a strong blue spark appears across the spark plug gap, it proves the condition is OK. Remember to check for corrosion on the terminals, as it can distort the signal. A faulty ignition coil doesn't just affect starting—it can also damage the engine, so early detection saves both money and hassle.
As an average rider, I use some DIY methods to test the ignition coil. For example, place a screwdriver near the spark plug terminal and start the engine to see if there's a spark. A visible spark means it's working, while a dim red glow or no spark indicates it needs replacement. Another simple test is measuring resistance with a multimeter—no need for expensive tools, a $30 multimeter will do. Resistance below 1 ohm is normal; higher means it's faulty. Safety-wise, I never force things because a faulty ignition coil can burn wires or damage the battery. For routine maintenance, I check the resistance every six months to avoid breakdowns on the road. If the ignition coil is aging, you'll notice unstable starts and frequent stalling when stopping—replace it promptly for hassle-free and safe riding.
