mxu 500 irs efi Manuale-dofficina : Pagina 145

          8. CYLINDER HEAD/VALVES                                                        MXU 500 IRS


 SERVICE INFORMATION
 GENERAL INSTRUCTIONS
 · The cylinder head can be serviced with the engine installed in the frame. Coolant in the radiator
   and water jacket must be drained first.
 · When assembling, apply molybdenum disulfide grease or engine oil to the valve guide movable
   parts and valve arm sliding surfaces for initial lubrication.
 · The valve rocker arms are lubricated by engine oil through the cylinder head engine oil passages.
   Clean and unclog the oil passages before assembling the cylinder head.
 · After disassembly, clean the removed parts and dry them with compressed air before inspection.
 · After removal, mark and arrange the removed parts in order. When assembling, install them in
   the reverse order of removal.




 SPECIFICATIONS                                                                         Unit: mm
            Item                                     Standard                    Service Limit
                               IN      0.1 mm                                         
 Valve clearance (cold)
                               EX      0.1 mm                                         
 Cylinder head compression pressure    15 kg/cm2                                      
 Cylinder head warpage                                                      0.05
 Camshaft runout                                                            0.05
                               IN      37.2614                              37.11
 Camshaft cam height
                               EX      37.0084                              36.86
                               IN      10 10.015                            10.1
 Valve rocker arm I.D.
                               EX      10 10.015                            10.1
 Valve rocker arm shaft        IN      9.975 9.99                           9.9
 O.D.                          EX      9.9759.99                            9.9
 Rocker arm to shaft clearance         0.009 0.042                          0.1
                               IN      4.975 4.99                           4.925
 Valve stem O.D.
                               EX      4.955 4.97                           4.915
                               IN      5 5.015                              5.03
 Valve guide I.D.
                               EX      5 5.015                              5.03
 Valve stem-to-guide           IN      0.01 0.037                           0.08
 clearance                     EX      0.03 0.057                           0.1




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