KYMCO PEOPLE S 125 Service Manual

8. CYLINDER/PISTON
8-2
PEOPLE S 4T
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.
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 White 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
SPECIFICATIONS
Item (50cc) Standard (mm) Service Limit (mm)
I.D.
39.000～39.010
39.10
Warpage
⎯
0.05
Cylindricity
⎯
0.05
True roundness
⎯
0.05
Ring-to-groove Top
0.015～0.055
0.09
clearance Second
0.015～0.055
0.09
Top
0.15～0.30
0.5
Piston, Ring end gap Second
0.15～0.30
0.5
piston ring Oil side rail
0.2～0.7
⎯
Piston O.D.
39.985～59.995
39.9
Piston O.D. measuring position 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
0.02
Connecting rod small end I.D. bore
13.016～13.034
13.06
Cylinde
r

KYMCO PEOPLE S 125 Specifications

General

Displacement	124.6 cc
Front Suspension	Telescopic Fork
Cooling System	Air Cooled
Max Torque	10.4 Nm @ 6500 rpm
Transmission	CVT
Front Brake	Disc