7. CYLINDER/PISTON Pulsar CK 125
SERVICE INFORMATION.......................7-1 CAM FOLLOWER REMOVAL ............... 7-2
TROUBLESHOOTING..............................7-1 PISTON REMOVAL/INSTALLATION... 7-2
CYLINDER REMOVAL ...........................7-2 CYLINDER INSTALLATION ................. 7-7
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.
Item Standard (mm)
I.D. 56.556.6
Warpage
Cylinder
Cylindricity 0.01
True roundness 0.01
Ring-to-groove Top 0.50.75
clearance Second 0.50.75
Top 0.150.35
Piston/ Ring end gap Second 0.150.35
piston Oil side rail 0.20.5
ring Piston O.D. 56.4556.48
Piston O.D. measuring position 10mm from bottom of skirt
Piston-to-cylinder clearance 0.010.075
Piston pin hole I.D. 15.00215.008
Piston pin O.D 14.915
Piston-to-piston pin clearance 0.0010.007
Connecting rod small end I.D. 15.0115.028
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 Excessive smoke from exhaust muffler
· Worn, stuck or broken piston rings · Worn or damaged piston rings
· Worn or damaged cylinder or piston · Worn or damaged cylinder or piston
Compression too high Abnormal noisy piston
· Excessive carbon build-up in combustion · Worn cylinder, piston or piston rings
chamber or on piston head · Worn piston pin hole or piston pin
7-1
Fast delivery and good communication ! The parts fit perfectly ! Thank you very much ! 
4.7 / 5