KYMCO Super 8 50 Service Manual

8. CYLINDER/PISTON
8-1
Super 8 50
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.
39.00-39.01
39.1
Warpage

0.05
Cylindricity

0.05
True roundness

0.05
Ring-to-groove
Top
0.015-0.050
0.09
clearance
Second
0.015-0.050
0.09
Top
0.06-0.16
0.45
Piston,
Ring end gap
Second
0.13-0.28
0.45
piston ring
Oil side rail
0.20-0.70

Piston O.D.
38.855-38.875
38.8
Piston O.D. measuring position
8mm 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
SERVICE INFORMATION ....................... 8-1 PISTON REMOVAL ................................. 8-2
TROUBLESHOOTING .............................. 8-1 PISTON INSTALLATION ........................ 8-6
CYLINDER REMOVAL ............................ 8-2 CYLINDER INSTALLATION .................. 8-6
Cylinder

KYMCO Super 8 50 Specifications

General

Displacement	49.5 cc
Fuel System	Carburetor
Ignition	CDI
Front Suspension	Telescopic Fork
Front Brake	Disc
Rear Brake	Drum
Front Tire	120/70-12
Rear Tire	130/70-12
Cooling System	Air
Transmission	CVT Automatic
Seat Height	780 mm
Wheelbase	1, 280 mm