vitality 50 2t 4t 1 Manuel atelier : Page 44

          2. GENERAL INFORMATION                                                          VITALITY 50

 POOR PERFORMANCE (AT HIGH SPEED)



 Inspection/Adjustment                     Symptom                       Probable Cause


 Check ignition timing



                                                                      Faulty CDI unit
                            Correct timing       Incorrect timing
                                                                      Faulty pulser coil
                                                                      The woodruff key in the
 Check carburetor pilot                                               crankshaft is not fix position.
 screw adjustment

                                                                      Improperly adjusted valve
                          Correctly adjusted   Incorrectly adjusted   clearance
                                                                      Worn valve seat
 Check fuel pump for
 fuel supply
                                                                      Empty fuel tank
                                                                      Clogged fuel tube or filter
                          Fuel flows freely    Fuel flow restricted   Clogged Fuel tank cap breather
                                                                      hole
                                                                      Faulty auto fuel valve
 Check carburetor jets
 for clogging


                             Not clogged              Clogged         Clean and unclog


 Check valve timing


                               Correct                Incorrect       Cam timing gear aligning marks
                                                                      not aligned

 Check valve spring
 tension


                            Not weakened             Weak spring      Faulty spring




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