Page 1439 - Foton Workshop Manual - Tunland (AT)
P. 1439

ENGINE MECHANICAL - CYLINDER HEAD,VALVE                          15-65

                                                           (a)    Check whether the valve has carbon deposits.
                                                                  If so, clean the valve thoroughly with steel
                                                                  brush.








                                                                                                                     15





                                                           (b)    Check whether the working surface of the
                                                                  valve and the valve seat is airtight. If not,
                                                                  polish it with a valve polisher. The contact
                                                                  surface of the valve seat shall be consistent
                                                                  with the center of the valve working face.
                                                           (c)    Check whether the valve has ablation, dents
                                                                  and carbon stains, and if so, remove them.
                                                           (d)    Check whether the angle of the valve surface
                                                                  is 45 degrees. If not, grind it to 45 degrees.




                                                           (e)    Check the valve head thickness.

                                                                  Intake valve head thickness limit: 1.10mm
                                                                  Exhaust valve head thickness limit:1.90mm

                                                                NOTICE
                                                           If the intake or exhaust valve head thickness is
                                                           less than the minimum, the replacement the
                                                           valve.
                                                           (f)    Check valve surface indentation tat must be
                                                                  around 360 degrees and concentric with the
                                                                  valve, otherwise replace the valve.

                                                           (g)    Check the total height of the valve. Replace
                                                                  it if below limit:
                                                                NOTICE

                                                           •      If the top surface of the valve stem is worn,
                                                                  grind the valve surface with the grinding
                                                                  rod or replace the valve.
                                                           •      The valve length must not be reduced to
                                                                  less than the minimum.












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