dink 50 125 1 Manuel atelier : Page 149

          7. CYLINDER/PISTON                                                                              DINK50/ 125



 SPECIFICATIONS(DINK 50)                                                                     Unit: mm (in)
                        Item                                       Standard                 Service Limit
                   I.D.                              39.0039.01 (1.5601.5604)              39.1(1.564)
                   Warpage                                                                 0.05 (0.002)
     Cylinder
                   Cylindricity                                                            0.05 (0.002)
                   True roundness                                                          0.05 (0.002)
                   Ring-to-groove    Top             0.0150.055 (0.0060.002)               0.09 (0.0036)
                   clearance         Second          0.0150.055(0.0060.002)                0.09 (0.0036)
                                     Top             0.100.3 (0.0040.012)                  0.5 (0.02)
     Piston,       Ring end gap      Second          0.100.3 (0.0040.012)                  0.5 (0.02)
     piston ring                     Oil side rail   0.20.7 (0.0080.032)                           
                   Piston O.D.                       39.98539.995(1.59941.5998)            39.9 (1.596)
                   Piston O.D. measuring position    9 mm (0.36 in) from bottom of skirt           
 .                 Piston-to-cylinder clearance      0.010.04 (0.00040.0016)               0.1 (0.004)
                   Piston pin hole I.D.              13.00213.008 (0.520080.52032)         13.04 (0.536)
 Piston pin O.D                                      14.99415 (0.599760.6)                 14.96 (0.5984)
 Piston-to-piston pin clearance                      0.0020.014 (0.000080.00056)           0.02 (0.0008)
 Connecting rod small end I.D. bore                  13.01613.034 (0.520640.52136)         13.06 (0.5224)

 TROUBLESHOOTING
 · When hard starting or poor performance at low speed occurs, check the crankcase breather for
   white smoke. If white smoke is found, it means that the piston rings are worn, stuck or broken.

 Compression too low or uneven
 compression                                               Excessive smoke from exhaust muffler
 · Worn or damaged cylinder and piston rings               · Worn or damaged piston rings
 · Worn, stuck or broken piston rings                      · Worn or damaged cylinder and piston

 Compression too high                                      Abnormal noisy piston
 · Excessive carbon build-up in combustion                 · Worn cylinder, piston and piston rings
   chamber or on piston head                               · Worn piston pin hole and piston pin
                                                           · Incorrectly installed piston




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