If your dirt bike's spark plug wire produces a spark when you touch it but doesn't generate a spark when you insert a spark plug, it could indicate an issue with the spark plug itself or its connection. Here are a few potential reasons for this problem:
Faulty spark plug: The spark plug might be damaged or worn out, preventing it from creating a spark. Inspect the spark plug for signs of fouling, such as excessive carbon buildup or oil deposits. If the plug looks worn or damaged, replacing it with a new one should solve the issue.
Improper gap: The spark plug gap refers to the distance between the center and ground electrodes. It's crucial to set the gap correctly as specified by the dirt bike's manufacturer. If the gap is too wide or too narrow, the spark may not be able to jump across and ignite the fuel-air mixture. Use a gap tool to adjust the spark plug gap accurately.
Poor connection: Ensure that the spark plug is tightly connected to the spark plug wire. A loose or weak connection can prevent the transfer of electrical current, resulting in no spark. Disconnect the spark plug wire, clean the terminal, and firmly reconnect it to the spark plug.
Ignition system issues: The problem may not be directly related to the spark plug but rather the ignition system. Check the ignition coil, ignition module, and any associated wiring for signs of damage or malfunction. Faulty components in the ignition system can disrupt the spark generation process.
Other electrical issues: Examine the wiring and electrical connections throughout the bike for any loose, damaged, or corroded parts. Faulty wiring or electrical components can interfere with the spark plug's performance.
If you have attempted these troubleshooting steps and are still unable to resolve the issue, it may be beneficial to consult a professional mechanic or a dirt bike specialist who can diagnose and repair the problem more accurately.