2. GENERAL INFORMATION VITALITY 50 POOR PERFORMANCE (ESPECIALLY AT IDLE AND LOW SPEEDS) Inspection/Adjustment Symptom Probable Cause Check ignition timing. Correct timing Incorrect timing Faulty CDI unit Faulty A.C. generator Check carburetor air screw adjustment. Mixture too rich (turn screw Correctly adjusted Incorrectly adjusted out) Mixture too lean (turn screw in) Check carburetor gasket for air leaks. Carburetor not securely No air leak Air leaks tightened Faulty intake manifold gasket Remove spark plug and Deformed carburetor O-ring install it into spark plug cap to test spark by connecting it to engine ground. Faulty or fouled spark plug Faulty CDI unit Good spark Weak or inter- Faulty A.C. generator mittent spark Faulty ignition coil Broken or shorted high Remove auto bystarter tension wire connecting wire and Faulty ignition switch check if bypass fuel line is clogged. Broken auto bystarter wire Not clogged Clogged Connect auto bystarter Faulty auto bystarter wire to battery. Wait for 5 minutes, then connect a hose to fuel enriching circuit and then blow the hose with mouth. Clogged Not clogged 2-29