CBF 125 AIR COOLING ENGINE SERVICE MANUAL
RENEGADE SPORT & SCRAMBLER X 125 EFI
44
5.2
Limits for service
Cylinder and Piston
unit
:
mm
Item
Standard value
Service Limit
Cylinder
Inner diameter of cylinder
Φ52.400
~
φ57.410
Φ52.5
Cylindricity
0.004
0.10
Flatness
of cylinder face
0.03
0.10
Piston, Piston
Ring and
Piston Pin
Outer diameter of piston
Φ52.38
~
φ52.39
Φ52.3
Inner diameter of piston pin hole
φ14.002
~
φ14.008
φ14.04
Closure clearance of
piston ring
Top
0.1
~
0.25
0.35
Second
0.15-0.30
0.4
Oil ring
0.2
~
0.7
0.85
gap between piston
rings and piston rings
Top
0.02
~
0.06
0.10
Second
0.02
~
0.06
0.10
Piston/Cylinder Clearance
0.01
~
0.03
0.07
Outer diameter of piston pin
φ13.994
~
φ14
φ13.96
Clearance between piston pin and piston
pin hole
0.002
~
0.014
0.04
Small End of
Connecting
Rod
Inner diameter
φ14.015
~
φ14.028
φ14.06
Clearance
between
small
end
of
connecting rod and piston pin
0.015
~
0.03
0.10
Tightening torque of AB bolt: 11N.m
5.3
Troubleshooting
5.3.1.
Cylinder pressure is too low or there is no cylinder pressure (performance at low speed is
not acceptable)
•
Severely worn or broken piston ring
•
Damaged or broken cylinder block or piston
5.3.2.
Cylinder pressure is too high. Engine overheats.
•
Too much carbon deposit on piston top
5.3.3.
Engine oil is consumed significantly, and engine smokes heavily.
•
Severely worn or broken cylinder block and piston
•
Improper assembly of piston ring
5.3.4.
Abnormal noise
•
Improper assembly of piston
•
Fit clearance is too large between piston and piston pin, and the cylinder block and
piston are severely worn.