2005 YAMAHA VX110 Service Manual

5-78
EPOWRCRANKCASE
5. Tighten:
Crankcase bolts 1
–0

NOTE:
Do not reuse crankcase bolts 1
–0
.
The tightening procedure of crankcase bolts
1
–0
is angle controlled, therefore tighten
the bolts using the following procedure.
Tightening steps:
Tighten the bolts in the order of the num-
bers on the crankcase.
T R..
Crankcase bolt
1–
0:
1st:
7.8 N  m
(0.78 kgf  m, 5.6 ft  lb)
Loosen and retighten the crankcase bolts
in the proper tightening sequence as
shown.
T R..
Crankcase bolt
1–
0:
2nd:
Loosen completely
3rd:
15 N  m (1.5 kgf  m, 11 ft  lb)
Tighten the crankcase bolts further to
reach the specified angle 49° in the
proper tightening sequence as shown.
T R..
Crankcase bolt
1–
0:
Final:
Specified angle 49
± 5°
WARNING
When the bolts are tightened more than
the specified angle, do not loosen the
bolt and then retighten it.
Replace the bolt with a new one and per-
form the procedure again.
15397
ICAEG
86240
HFBDJ
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5-79
EPOWRCRANKCASE
CAUTION:
Do not use a torque wrench to tighten
the bolt to the specified angle.
Tighten the bolt until it is at the speci-
fied angle.
NOTE:
When using a hexagonal bolt, note that the
angle from one corner to another is 60°.
6. Tighten:
Crankcase bolts A
–J

NOTE:
Tighten the bolts in the order of the numbers
on the crankcase.
7. Tighten:
Oil pan bolts
NOTE:
Tighten the bolts in the order of the numbers
on the oil pan.
T R..
Crankcase bolt
A–
J:
12 N  m (1.2 kgf  m, 8.7 ft  lb)
LOCTITE 572
T R..
Oil pan bolt:
12 N  m (1.2 kgf  m, 8.7 ft  lb)
LOCTITE 572
15397
ICAEG
86240
HFBDJ
106
24812
15
11
7
3 1 5 9
13 14
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5-80
EPOWRCONNECTING RODS AND PISTONS
CONNECTING RODS AND PISTONS
EXPLODED DIAGRAM
REMOVAL AND INSTALLATION CHART
Step Procedure/Part name Q’ty Service points
CONNECTING RODS AND
PISTONS REMOVALFollow the left “Step” for removal.
Crankcase Separate
Refer to “CRANKCASE”.
1Nut 8
2 Connecting rod cap 4
3 Big end lower bearing 4
4 Piston pin clip 8
5 Piston pin 4
6Piston 4
7 Connecting rod 4
EE
E
E
1 2 310
11
12
4
5
6
8
7
9
2nd 120 ± 5˚ 1st 20 N • m (2.0 kgf
• m, 14 ft
• Ib)
MM
MM
4
Not reusable
Not reusable
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5-81
EPOWRCONNECTING RODS AND PISTONS
EXPLODED DIAGRAM
Step Procedure/Part name Q’ty Service points
8Bolt 8
9 Big end upper bearing 4
10 Top ring 4
11 2nd ring 4
12 Oil ring 4
Reverse the removal steps for installation.
EE
E
E
1 2 310
11
12
4
5
6
8
7
9
2nd 120 ± 5˚ 1st 20 N • m (2.0 kgf
• m, 14 ft
• Ib)
MM
MM
4
Not reusable
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5-82
EPOWRCONNECTING RODS AND PISTONS
SERVICE POINTS
Connecting rod and piston removal
The following procedure applies to all of the
connecting rods and pistons.
1. Remove:
Connecting rod cap 1

Big end bearings
NOTE:
Identify the position of each big end bearing so
that it can be reinstalled in its original place.
1
2. Remove:
Piston pin clips 1

Piston pin 2
Piston 3
Connecting rod 4
CAUTION:
Do not use a hammer to drive the piston
pin out.
NOTE:
For reference during installation, put an iden-
tification number a on the piston crown.
Before removing the piston pin, deburr the
piston pin clip’s groove and the piston’s pin
bore area.
3. Remove:
Top ring
2nd ring
Oil ring
NOTE:
When removing a piston ring, open the end
gap with your fingers and lift the other side of
the ring over the piston crown.
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5-83
EPOWRCONNECTING RODS AND PISTONS
Cylinder and piston inspection
The following procedure applies to all of the
cylinders and pistons.
1. Check:
Piston wall
Cylinder wall
Vertical scratches →
Replace the cylin-
der, and the piston and piston rings as a
set.
2. Measure:
Piston-to-cylinder clearance
Measurement steps:
Measure cylinder bore “C” with the cylin-
der bore gauge.
Cylinder bore “C”76.000–76.015 mm
(2.9921–2.9927 in)
Taper limit “T”0.08 mm (0.003 in)
Out of round “R”0.05 mm (0.002 in)
“C” = maximum of D
1–D6
“T” = maximum of D
1–D5 (direction
c)
and D
2–D6 (direction
d)
“R” = maximum of D
2–D1 (measuring
point
a) and D
6–D5 (measuring point
b)
If out of specification, replace the cylin-
der, and the piston and piston rings as a
set.
Measure piston skirt diameter “P” with the
micrometer.
a
5 mm (0.2 in) from the bottom edge of the
piston
Piston size “P”
Standard75.895–75.910 mm
(2.9880–2.9986 in)
D1D2
D3D4
D5D6
c
d a
b
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5-84
EPOWRCONNECTING RODS AND PISTONS
If out of specification, replace the piston
and piston rings as a set.
Calculate the piston-to-cylinder clearance
with the following formula.
Piston-to-cylinder clearance = Cylinder
bore “C” – Piston skirt diameter “P”
Piston-to-cylinder clearance:
0.10–0.11 mm (0.0039–0.0043 in)
: 0.17 mm (0.0067 in)
If out of specification, replace the piston
and piston rings as a set.
Piston ring inspection
1. Measure:
Piston ring side clearance
Out of specification →
Replace the pis-
ton and piston rings as a set.
NOTE:
Before measuring the piston ring side clear-
ance, eliminate any carbon deposits from the
piston ring grooves and piston rings.
Side clearance:
Top ring:
0.030–0.065 mm
(0.0012–0.0026 in)
2nd ring:
0.020–0.055 mm
(0.0008–0.0022 in)
Oil ring:
0.040–0.160 mm
(0.0016–0.0063 in)
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5-85
EPOWRCONNECTING RODS AND PISTONS
2. Install:
Piston ring
(into the cylinder)
NOTE:
Level the piston ring in the cylinder with the
piston crown.
a5 mm (0.2 in)
3. Measure:
Piston ring end gap
Out of specification →
Replace the pis-
ton ring.
NOTE:
The oil ring expander spacer’s end gap cannot
be measured. If the oil ring rail’s gap is exces-
sive, replace all three piston rings.
Piston ring end gap:
Top ring:
0.32–0.44 mm
(0.0126–0.0173 in)
2nd ring:
0.43–0.58 mm
(0.0169–0.0228 in)
Oil ring:
0.10–0.35 mm
(0.0039–0.0138 in)
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