KYMCO ZING 150 User Manual

7. CYLINDER/PISTON
7
-
1
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
Standard
Service Limit
Item
125cc 150cc 125cc 150cc
I.D. 56.5～56.51 62～62.01 56.6 62.1
Warpage  
Cylindricity 0.01 0.05
Cylinder
True roundness 0.01 0.05
Top 0.45～0.7 0.9
Ring-to-
groove
clearance
Second 0.8～1.05 1.2
Top 0.1～0.3 0.5
Second 0.1～0.3 0.5
Ring end gap
Oil side rail 0.3～0.9 1.1
Piston O.D. 56.45～56.48 61.97～61.99 56.35 61.87
Piston O.D. measuring position 10mm from bottom of skirt

Piston-to-cylinder clearance 0.005～0.065 0.1
Piston/
piston
ring
.
Piston pin hole I.D. 15.002～15.008 15.012
Piston pin O.D 14.994～15 14.99
Piston-to-piston pin clearance 0.001～0.007 0.01
Connecting rod small end I.D. 15.01～15.028 15.032
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
SERVICE INFORMATION .......................7-1 CAM FOLLOWER REMOVAL ...............7-2
TROUBLESHOOTING..............................7-1 PISTON REMOVAL.................................7-2
CYLINDER REMOVAL............................7-2 CYLINDER INSTALLATION..................7-7
Unit: mm

KYMCO ZING 150 Specifications

General

Brand	KYMCO
Model	ZING 150
Category	Motorcycle
Language	English