agility 50 3 Workshop-manual : Page 87

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          8. CYLINDER/PISTON                                                                 AGILITY 50

 SERVICE INFORMATION.......................8-1      PISTON REMOVAL................................. 8-2
 TROUBLESHOOTING..............................8-1   PISTON INSTALLATION........................ 8-6
 CYLINDER REMOVAL ...........................8-2    CYLINDER INSTALLATION ................. 8-6


 SERVICE INFORMATION
 GENERAL INSTRUCTIONS
 · The cylinder and piston can be serviced with the engine installed in the frame.
 · After disassembly, clean the removed parts and dry them with compressed air before inspection.

 SPECIFICATIONS

                   Item                             Standard (mm)               Service Limit (mm)
             I.D.                                    50.00-50.01
             Warpage                                                                     0.05
 Cylinder
             Cylindricity                                                                0.05
             True roundness                                                              0.05
             Ring-to-         Top                    0.015-0.050                         0.09
             clearance        Second                 0.015-0.050                         0.09
                              Top                     0.08-0.20                          0.45
 Piston,     Ring end gap Second                      0.05-0.20                          0.45
 piston ring                  Oil side rail           0.20-0.70                           
             Piston O.D.                            49.97-49.990                         49.9
             Piston O.D. measuring             9mm from bottom of skirt                   
             Piston-to-cylinder clearance           0.010-0.040                           0.1
             Piston pin hole I.D.                  13.002-13.008                        13.04
 Piston pin O.D                                    12.994-13.000                        12.96
 Piston-to-piston pin clearance                     0.002-0.014                           
 Connecting rod small end I.D. bore                13.016-13.034                        13.06


 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, stuck or broken piston rings               · Worn or damaged piston rings
 · Worn or damaged cylinder and piston              · 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


8-1