18. IGNITION SYSTEM MXU 500 IRS SERVICE INFORMATION GENERAL INSTRUCTIONS Some electrical components may be damaged if terminals or connectors are connected or disconnected while the ignition switch is "ON" and current is present. When servicing the ignition system, always follow the steps in the troubleshooting on page 18-3. The ignition timing cannot be adjusted since the ignition control module is factory preset. The ignition control module may be damaged if dropped. Also, if the connector is disconnected when current is flowing, the excessive voltage may damage the ignition control module. Always turn off the ignition switch before servicing. A faulty ignition system is often related to poor connections. Check those connections before proceeding. Make sure the battery is adequately charged. Using the starter motor with a weak battery results in a slower engine cranking speed as well as no spark at the spark plug. Use a spark plug of the correct heat range. Using spark plug with an incorrect heat range can damage the engine. See section 17 for ignition pulse generator removal/installation. See section 20 for following components: TM Ignition switch TM Engine stop switch SPECIFICATIONS Item Standard Spark plug NGK-CR7E Spark plug gap 0.7 mm (0.028 in) Ignition system Full transistor digital ignition Ignition timing 5°/1500 rpm 18-2