1. GENERAL INFORMATION ZING125 POOR PERFORMANCE (ESPECIALLY AT IDLE AND LOW SPEEDS) Inspection/Adjustment Symptom Probable Cause Check ignition timing Correct Incorrect Faulty CDI unit Faulty pulser coil Check carburetor pilot screw adjustment Correctly adjusted Incorrectly adjusted Mixture too lean (turn screw in) Mixture too rich (turn screw out) Check carburetor gasket for air leaks Faulty intake manifold gasket Carburetor not securely No air leak Air leaks tightened Damaged insulator rubber Broken vacuum tube Remove spark plug and install it into spark plug cap to test spark by connecting it to engine ground Faulty or fouled spark plug Weak or inter- Faulty CDI unit Good spark Faulty A.C. generator mittent spark Faulty ignition coil Faulty ignition switch Check A.C. generator Faulty A.C. generator Good Faulty Damaged vacuum tube Clogged air vent hole 1-16