15. IGNITION SYSTEM ZING125 TROUBLESHOOTING Engine stalls immediately after it starts · Weak spark · Improper ignition timing · Faulty CDI unit No spark at plug · Faulty ignition switch · Poorly connected, broken or shorted wire -Between pulser coil, CDI unit and ignition coil -Between exciter coil and CDI unit -Between CDI unit and ignition coil -Between CDI unit and ignition switch -Between ignition coil and spark plug Engine starts but runs poorly · Faulty ignition coil · Poorly connected wire · Faulty spark plug · Spark plug cap electricity leakage · Faulty A.C. generator · Stator not installed properly (Loose) · Faulty CDI unit 15-2