kpw 125 Manuale-dofficina : Pagina 60

          6. CYLINDER HEAD/VALVES                                                                K-PIPE 125


 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 or broken valve stem or valve guide
                                                     · Damaged valve stem seal

 Compression too low
 · Incorrect valve clearance (too small)
 · Burned or bend valves                             Abnormal noise
 · Incorrect valve timing                            · Incorrect valve clearance (too large)
 · Broken valve spring                               · Burned valve or rocker arm
 · Poor valve and seat contact                       · Worn camshaft or cam follower
 · Leaking cylinder head gasket
 · Warped or cracked cylinder head
 · Poorly installed spark plug


 Compression too high
 · Excessive carbon build-up in combustion
   chamber or on piston head




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