1. GENERAL INFORMATION Mongoose/KXR 90/50 NO SPARK AT SPARK PLUG Inspection/Adjustment Symptom Probable Cause Replace with a new spark plug and inspect again Weak or no spark Good spark Faulty spark plug Check spark plug cap and high-tension wire for looseness Not loose Loose Loose spark plug cap Check CDI unit coupler for looseness Good Good Poorly connected coupler Measure resistance between terminals of CDI unit coupler Normal Abnormal Check related parts Faulty ignition switch Weak battery Normal Abnormal Faulty pulser coil Faulty ignition coil Faulty charging system Broken wire harness Poorly connected coupler Check CDI unit with a CDI unit tester Normal Abnormal Faulty CDI unit Check ignition coil with a CDI unit tester Abnormal Faulty ignition coil 1-30