TGB BLADE 250 Service Manual page 81

7. CYLINDER/PISTON
T
Precautions in Operation
General Information
y
Both cylinder and piston service cannot be carried out when engine mounted on frame.
UA25A
Specification
ID
Cylinder
Bend
Clearance between piston
rings
Piston/ Ring-end gap
Piston ring
OD of piston (2
Clearance between piston and cylinder
ID of piston pin boss
OD of piston pin
Clearance between piston and piston pin
ID of connecting rod small-end
Trouble Diagnosis
Low or Unstable Compression Pressure
● Cylinder or piston ring worn out
Knock or Noise
● Cylinder or piston ring worn out
● Carbon deposits on cylinder head top-side
● Piston pin hole and piston pin wear out
7-2
Item
Top ring
nd
2 ring
Top ring
nd
2 ring
Oil ring side rail
nd
)
Standard
70.995~71.015
-
0.015~0.050
0.015~0.050
0.150~0.300
0.300~0.450
0.200~0.700
70.430~70.480
0.010~0.040
17.002~17.008
16.994~17.000
0.002~0.014
17.016~17.034
Smoking in Exhaust Pipe
● Piston or piston ring worn out
● Piston ring installation improperly
● Cylinder or piston damage
Engine Overheat
● Carbon deposits on cylinder head top side
● Cooling pipe clogged or not enough in coolant
flow
Unit：mm
Limit
71.100
0.050
0.090
0.090
0.500
0.650
-
70.380
0.100
17.020
16.960
0.020
17.064