4. FUEL SYSTEM ZING125 TROUBLESHOOTING Engine cranks but won't start Engine lacks power · No fuel in tank · Clogged air cleaner · No fuel to carburetor · Faulty carburetor · Cylinder flooded with fuel · Faulty ignition system · No spark at plug · Clogged air cleaner Lean mixture · Intake air leak · Clogged carburetor fuel jets · Improper throttle operation · Float level too low · Intake air leak Engine idles roughly, stalls or runs poorly · Faulty charcoal canister · Excessively used choke · Restricted fuel line · Ignition malfunction · Faulty carburetor Rich mixture · Poor quality fuel · Float level too low · Lean or rich mixture · Clogged air jets · Clogged air cleaner · Clogged air cleaner · Incorrect idle speed · Restricted A.C.V. tube · Faulty charcoal canister · Worn throttle needle Misfiring during acceleration · Faulty ignition system · Faulty carburetor · Faulty accelerating pump · Faulty charcoal canister Backfiring at deceleration · Float level too low · Incorrectly adjusted carburetor · Faulty A.C.V. · Faulty exhaust muffler · Faulty A.I.C.V. 4-2