quannon 125 Workshop-manual : Page 28

          2. INSPECTION/ADJUSTMENT                                              QUANNON 125


  IGNITION TIMING
 · The CDI unit is not adjustable.
   · If the ignition timing is incorrect, check
     the ignition system.

  Remove the ignition timing eyes hole cap on
  the left crankcase cover.




                                                          Eyes Hole
  Check the ignition timing with a timing light.
  When the engine is running at idle speed,
  the ignition timing is correct if the index mark
  on the left crankcase cover aligns with the
  "F" mark on the flywheel.




                                                     Timing Light
                                                                        "F" Mark
  CYLINDER COMPRESSION
  Warm up the engine before compression
  test.
  Stop the engine, then remove the spark plug
  and insert a compression gauge.
  Open the throttle valve fully and crank the
  engine with the starter motor or kick lever.
  Measure the compression.
                           
  Compression: 13kg/cm



                                                              Compression Gauge
  If the compression is low, check for the
  following:
  Leaky valves
  Valve clearance too small
  Leaking cylinder head gasket
  Worn piston rings
  Worn piston/cylinder
  If the compression is high, it indicates that
  carbon deposits have accumulated on the
  combustion chamber and the piston head.



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