zing 125 qe Workshop-manual : Page 53

          6. CYLINDER HEAD/VALVES                                                             ZING II 125


 TORQUE VALUES
 Cylinder head nut               2.3~2.8 kg-m
 Cylinder head side bolt         0.8~1.2 kg-m
 Valve clearance adjusting nut   0.9 kg-m
 Cylinder head cover bolt        0.81.2 kg-m



 SPECIAL TOOLS
 Valve spring compressor         E040



 TROUBLESHOOTING
 · The poor cylinder head operation can be diagnosed by a compression test or by tracing engine
   top-end noises.


 Poor performance at idle speed                     White smoke from exhaust muffler
 · Compression too low                              · Worn valve stem or valve guide
                                                    · Damaged valve stem oil seal
 Compression too low
 · Incorrect valve clearance adjustment             Abnormal noise
 · Burned or bend valves                            · Incorrect valve clearance adjustment
 · Incorrect valve timing                           · Sticking valve or broken valve spring
 · Broken valve spring                              · Damaged or worn camshaft
 · Poor valve and seat contact                      · Worn cam chain tensioner
 · Leaking cylinder head gasket                     · Worn camshaft and rocker arm
 · Warped or cracked cylinder head
 · Poorly installed spark plug

 Compression too high
 · Excessive carbon build-up in combustion
   chamber




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