like 50 2T 1 Manuale-dofficina : Pagina 26

          2. GENERAL INFORMATION                                                        LIKE 50 2T

 ENGINE STOPS IMMEDIATELY AFTER IT STARTS

 Inspection/Adjustment                   Symptom                       Probable Cause

 Check if fuel reaches
 carburetor by
 loosening drain
 screw.
                                                                       Empty fuel tank
                              Fuel reaches       Fuel does not         Clogged float valve
                              carburetor         reach carburetor      Clogged charcoal canister
                                                                       Clogged fuel filter
                                                                       Faulty auto fuel valve
 Remove spark plug
 and install it into
 spark plug cap to test
 spark by connecting it
 to engine ground.
                           Plug not fouled or     Plug fouled or       Fouled spark plug
                           discolored             discolored           Incorrect heat range plug
 Remove spark plug
 and install it into
 spark plug cap to test
 spark by connecting it                                                Fouled spark plug
 to engine ground.                                                     Faulty CDI unit
                                                   Weak or inter-      Faulty A.C. generator
                              Good spark           mittent spark       Faulty ignition coil
                                                                       Broken or shorted high
                                                                       tension wire
 Test cylinder                                                         Faulty ignition switch
 compression (using a
 compression gauge).
                                                                       Worn cylinder and piston
                                                                       rings
                              Normal                Abnormal           Blown cylinder head gasket
                              compression           compression        Flaws in cylinder head
                                                                       Faulty reed valve
                                                                       Seized piston
 Check carburetor for
 clogging.


                             Not Clogged             Clogged           Clogged carburetor jets


 Check ignition timing.

                                                                       Faulty CDI unit or A.C.
                             Correct timing       Incorrect timing     generator
                                                                       A.C.G. flywheel not aligned

 Check carburetor air
 screw adjustment.

                                                                       Mixture too rich (turn screw
                          Correctly adjusted    Incorrectly adjusted   out)
                                                                       Mixture too lean (turn
                                                                       screw in)




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