zing 125 qe Workshop-manual : Page 16

          1. GENERAL INFORMATION                                                                ZING125

 TROUBLESHOOTING
 ENGINE WILL NOT START OR IS HARD TO START

                                                Symptom
 Inspection/Adjustment                                                    Probable Cause

 Check if fuel reaches
 carburetor by loosening
 drain screw                                                            Empty fuel tank
                                                                        Clogged fuel line between fuel
                                                                        tank and carburetor
                                Fuel reaches         Fuel does not      Clogged float oil passage
                                carburetor           reach carburetor   Clogged fuel filter
                                                                        Clogged charcoal canister
                                                                        Clogged auto fuel valve strainer
 Remove spark plug and                                                  Faulty auto fuel valve passage
 install it into spark plug                                             Clogged carburetor air balance
 cap to test spark by                                                   tube
 connecting it to engine
 ground
                                                                        Faulty spark plug
                                                                        Fouled spark plug
                                                                        Faulty CDI unit
                                Spark jumps         Weak or no spark    Faulty pulser coil
                                                                        Faulty exciter coil
                                                                        Faulty ignition switch
                                                                        Broken or shorted ignition coil
                                                                        wire
 Test cylinder
 compression
                                                                        Faulty or slipping clutch
                                Normal                 Low or no        Valve clearance too small
                                compression            compression      Valve stuck open
                                                                        Worn cylinder and piston rings
                                                                        Leaking cylinder head gasket
 Start engine by follow-
 ing normal starting
 procedure

                                                                        Faulty choke control system
                              Engine does not        Engine fires but   Leaking intake manifold
                              fire                   does not start     Incorrect ignition timing
                                                                        Incorrectly adjusted pilot screw

 Remove spark plug and
 inspect again

                                                      Wet spark plug    Flooded carburetor
                               Dry spark plug                           Throttle valve excessively open
                                                                        Clogged air cleaner




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