Honda CB160 Shop Manual page 42

38
fig. 3. l 03 Measuring piston ring gap
fig. 3. l 04_ Ring tension measurement
c : : : = = : : l ~
C = : J
c::====>
GOOD NOTGOOO
c::::::=::::::Jc:=:=:1
~c::::==I'
NOT GOOD NOT GOOD
= =
=c:::=
NOTGOOO NOT GOOD
fig. 3. 105 Profile of piston ring gop
3. ENGINE
I.
Inspection
1 . When the piston ring has been removed, it should
be fitted with the gap approximately 15 mm (.6"1
from skirt of the cylinder at a right angle to the
center line. Measurement of the gap should be
made with a thickness gauge. (Refer to Fig.
3. 105)
Standard value
Correction limit
Tcip ring
0.15 to 0.35 mm
When over
1.006" to .014
11
)
0.8 mm (.03"1,
replacement
should be made.
2nd ring
0.15 to 0.35 mm
Same as above
1.006° to .014
11
1
Oil ring
0.10 to 0.30 mm
Same as above
1.0039
11
to .011
11
1
2. Tension of the piston ring is measured with a ten-
sion measuring instrument as shown in the figure.
(Refer to Fig. 3. 104)
Standard value
Correction limit
Top ring 0.55±0.12kg
When over
ll .2 lb±.3 lbl
0.8 kg, replace-
menl should be
made.
2nd ring
0.55±0.12kg
Same as above
ll.2 lb±.3 lbl
Oil ring
0.75±0.15kg
Some as above
ll.65 lb±.33 lbl
II.
Replacing piston rings
1. When a piston ring is reassembled, it should be
fitted to the cylinder. Inspection should be made
to determine if the gaf)S
¢ ·
!he top and second
rings are between 0 and 0.30 mm (.011 "l and of
the oil ring between 0.1 0 (.0039) to 0.30 mm
1.011 "). If the gaps are somewhat less, they
should be dressed with a file.
(CAUTION)
{a) When a gap is dressed with a file, adjust-
ment should be made at a right angle due to
right angle fitting.
lb) If the piston ring gap is too small, seizure
between the ring and cylinder occurs due to
thermal expansion : if the gap is too large, oil
penetration or gas leakage occurs. (Refer to
Fig. 3. 105)