Yamaha 2007 R6 Service

							CONNECTING RODS AND PISTONS
5-62
NOTE:
Level the piston ring into the cylinder with the 
piston crown.
3. Measure:
•Piston ring end gap
Out of specification → Replace the piston 
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.
EAS24440
CHECKING THE PISTON PINS
The following procedure applies to all of the pis-
ton pins.
1. Check:
•Piston pin
Blue discoloration/grooves → Replace the 
piston pin and then check the lubrication sys-
tem.
2. Measure:
•Piston pin outside diameter “a”
Out of specification → Replace the piston pin.3. Measure:
•Piston pin bore diameter “b”
Out of specification → Replace the piston.
4. Calculate:
•Piston-pin-to-piston-pin-bore clearance
Out of specification → Replace the piston pin 
and piston as a set.
a. 5 mm (0.20 in)
 
Piston ring
Top ring
End gap (installed)
0.25–0.35 mm (0.0098–0.0138 
in)
Limit
0.55 mm (0.0217 in)
2nd ring
End gap (installed)
0.70–0.80 mm (0.0276–0.0315 
in)
Limit
1.00 mm (0.0394 in)
Oil ring
End gap (installed)
0.10–0.35 mm (0.0039–0.0138 
in)
 
Piston pin outside diameter
14.991–15.000 mm (0.5902–
0.5906 in)
Limit
14.971 mm (0.5894 in)
 
Piston pin bore inside diameter
15.002–15.013 mm (0.5906–
0.5911 in)
Limit
15.043 mm (0.5922 in)
•Piston-pin-to-piston-pin-bore clearance =
Piston pin bore diameter “b” -
Piston pin outside diameter “a”
 
Piston-pin-to-piston-pin-bore 
clearance
0.002–0.022 mm (0.00007–
0.00068 in) 
						

							CONNECTING RODS AND PISTONS
5-63
ET2C01013
CHECKING THE CONNECTING RODS
1. Measure:
•Crankshaft-pin-to-big-end-bearing clearance
Out of specification → Replace the big end 
bearings.



 
 
 








 
 



 
 



 
 







The following procedure applies to all of the 
connecting rods.
CAUTION:
ECA13930
Do not interchange the big end bearings and 
connecting rods. To obtain the correct 
crankshaft-pin-to-big-end-bearing clear-
ance and prevent engine damage, the big 
end bearings must be installed in their origi-
nal positions.
a. Clean the big end bearings, crankshaft pins, 
and the inside of the connecting rods halves.
b. Install the big end upper bearing into the con-
necting rod and the big end lower bearing into 
the connecting rod cap.
NOTE:
Align the projections “a” on the big end bearings 
with the notches “b” in the connecting rod and 
connecting rod cap.
c. Put a piece of Plastigauge
® “1” on the crank-
shaft pin.d. Assemble the connecting rod halves.
NOTE:
•Do not move the connecting rod or crankshaft 
until the clearance measurement has been 
completed.
•Lubricate the bolt threads and nut seats with 
molybdenum disulfide grease.
•Make sure the “Y” mark “c” on the connecting 
rod faces towards the left side of the crank-
shaft.
•Make sure the characters “d” on both the con-
necting rod and connecting rod cap are 
aligned.
e. Tighten the connecting rod nuts.
Refer to “INSTALLING THE CONNECTING 
RODS AND PISTONS” on page 5-64.
f. Remove the connecting rod and big end 
bearings.
Refer to “REMOVING THE CONNECTING 
RODS AND PISTONS” on page 5-60.
g. Measure the compressed Plastigauge
® width 
“e” on the crankshaft pin.
If the crankshaft-pin-to-big-end-bearing 
clearance is out of specification, select re-
placement big end bearings.
 
Oil clearance (using plasti-
gauge
®)
0.037–0.061 mm (0.0015–0.0024 
in)
1
d
c 
						

							CONNECTING RODS AND PISTONS
5-64
         
2. Select:
•Big end bearings (P
1–P4)
NOTE:
•The numbers stamped into the crankshaft web 
and the numbers on the connecting rods are 
used to determine the replacement big end 
bearing sizes.
•P
1–P4 refer to the bearings shown in the crank-
shaft illustration.For example, if the connecting rod P
1 and the 
crankshaft web P
1 numbers are 5 and 1 re-
spectively, then the bearing size for P
1 is:
EAS26170
INSTALLING THE CONNECTING RODS AND 
PISTONS
The following procedure applies to all of the pis-
tons and connecting rods.
1. Install:
•Top ring “1”
•2nd ring “2”
•Upper oil ring rail “3”
•Oil ring expander “4”
•Lower oil ring rail “5”
NOTE:
Be sure to install the piston rings so that the 
manufacturer’s marks or numbers “a” face up.
2. Install:
•Piston “1”
(onto the respective connecting rod “2”)
•Piston pin “3”
•Piston pin clips “4” 
NOTE:
•Apply engine oil onto the piston pin.
•Make sure that the “Y” mark “a” on the connect-
ing rod left when the punch mark “b” on the pis-
ton is pointing up. Refer to the illustration.
•Install the piston pin clips, so that the clip ends 
are 3 mm (0.12 in) “c” or more from the cutout 
in the piston.
•Reinstall each piston into its original cylinder 
(numbering order starting from the left: #1 to 
#4).
e
P1
P2P3
P4
2 1 1 2 2 1 1 1 1
P1P2P3P4
5 F
P1 (connecting rod) - P1 (crankshaft)
=
5 - 1 = 4 (green)
 
Bearing color code
1.Blue 2.Black 3.Brown 4.Green
New 
						

							CONNECTING RODS AND PISTONS
5-65
3. Offset:
•Piston ring end gaps
4. Lubricate:
•Piston
•Piston rings
•Cylinder
(with the recommended lubricant)
5. Lubricate:
•Bolt threads
•Nut seats
(with the recommended lubricant)6. Lubricate:
•Crankshaft pins
•Big end bearings
•Connecting rod inner surface
(with the recommended lubricant)
7. Install:
•Big end bearings
•Connecting rod and piston assembly
•Connecting rod cap
NOTE:
•Align the projections on the big end bearings 
with the notches in the connecting rods and 
connecting rod caps.
•Be sure to reinstall each big end bearing in its 
original place.
•While compressing the piston rings one hand, 
install the connecting rod assembly into the cyl-
inder with the other hand.
•Make sure the “Y” marks “a” on the connecting 
rods face towards the left side of the crank-
shaft.
•Make sure the characters “b” on both the con-
necting rod and connecting rod cap are 
aligned.
8. Tighten:
•Connecting rod nuts “1”
a. Top ring
b. Upper oil ring rail
c. Oil ring expander
d. 2nd ring
e. Lower oil ring rail
A. Exhaust side
 
Recommended lubricant
Engine oil
1
b 3a
2
4
4
4c
90˚ 
90˚ 
45˚ 
a.c  b d.e
A
 
Recommended lubricant
Molybdenum disulfide oil
 
Recommended lubricant
Engine oil
5F
ab 
						

							CONNECTING RODS AND PISTONS
5-66



 
 
 








 
 



 
 



 
 







WARNING
EW2C01007
Replace the connecting rod bolts and nuts 
with new ones.
NOTE:
Tighten the connecting rod nuts using the follow-
ing procedure.
a. Tighten the connecting rod nuts with a torque 
wrench.
b. Put a mark “1” on the corner of the connecting 
rod nut “2” and the connecting rod “3”.
c. Tighten the connecting rod nuts further to 
reach the specified angle 175°–185°.
WARNING
EWA13400
If the connecting rod nut is tightened more 
than the specified angle, do not loosen the 
nut and then retighten it. Instead, replace the 
connecting rod bolt and nut with a new one 
and perform the procedure again.
CAUTION:
ECA13950
Do not use a torque wrench to tighten the 
connecting rod nut to the specified angle.
NOTE:
On a hexagonal nut, note that the angle from 
one corner to another is 60°.
          
T R.. 
Connecting rod nut (1st)
15 Nm (1.5 m·kg, 11 ft·lb)
T R.. 
Connecting rod nut (final)
Specified angle 175°–185° 
						

							CRANKSHAFT
5-67
EAS25960
CRANKSHAFT
Removing the crankshaft
Order Job/Parts to remove Q’ty Remarks
CrankcaseSeparate.
Refer to “CRANKCASE” on page 5-55.
Connecting rod capsRefer to “CONNECTING RODS AND PIS-
TONS” on page 5-59.
1 Crankshaft 1
2 Crankshaft journal lower bearing 5
3 Crankshaft journal upper bearing 5
4 Oil nozzle 4
For installation, reverse the removal proce-
dure.
1 2
3
E
E
E
4
New
LS 
						

							CRANKSHAFT
5-68
EAS26040
REMOVING THE CRANKSHAFT JOURNAL 
BEARINGS
1. Remove:
•Crankshaft journal lower bearings
(from the lower crankcase)
•Crankshaft journal upper bearings
(from the upper crankcase)
NOTE:
Identify the position of each crankshaft journal 
bearing so that it can be reinstalled in its original 
place.
ET2C01018
CHECKING THE OIL NOZZLES
The following procedure applies to all of the oil 
nozzles.
1. Check:
•Oil nozzle
Damage/wear → Replace the oil nozzle.
•O-ring
Damage/wear → Replace.
•Oil passage
Obstruction → Blow out with compressed air.
EAS26070
CHECKING THE CRANKSHAFT AND 
CONNECTING RODS
1. Measure:
•Crankshaft runout
Out of specification → Replace the crank-
shaft.
2. Check:
•Crankshaft journal surfaces
•Crankshaft pin surfaces
•Bearing surfaces
Scratches/wear → Replace the crankshaft.3. Measure:
•Crankshaft-journal-to-crankshaft-journal-
bearing clearance
Out of specification → Replace the crank-
shaft journal bearings.
CAUTION:
ECA13920
Do not interchange the crankshaft journal 
bearings. To obtain the correct crankshaft-
journal-to-crankshaft-journal-bearing clear-
ance and prevent engine damage, the crank-
shaft journal bearings must be installed in 
their original positions.



 
 
 








 
 



 
 



 
 



 



a. Clean the crankshaft journal bearings, crank-
shaft journals, and bearing portions of the 
crankcase.
b. Place the upper crankcase upside down on a 
bench.
c. Install the crankshaft journal upper bearings 
“1” and the crankshaft into the upper crank-
case.
NOTE:
Align the projections “a” on the crankshaft jour-
nal upper bearings with the notches “b” in the up-
per crankcase.
d. Put a piece of Plastigauge
® “1” on each 
crankshaft journal.
NOTE:
Do not put the Plastigauge® over the oil hole in 
the crankshaft journal.
 
Runout limit C
0.030 mm (0.0012 in)
 
Journal oil clearance (using plas-
tigauge
®)
0.020–0.044 mm (0.0008–0.0017 
in) 
						

							CRANKSHAFT
5-69
e. Install the crankshaft journal lower bearings 
“1” into the lower crankcase and assemble 
the crankcase halves.
NOTE:
 Align the projections “a” of the crankshaft jour-
nal lower bearings with the notches “b” in the 
lower crankcase.
 Do not move the crankshaft until the clearance 
measurement has been completed.
f. Tighten the bolts to specification in the tight-
ening sequence cast on the crankcase.
Refer to “CRANKCASE” on page 5-55.
g. Remove the lower crankcase and the crank-
shaft journal lower bearings.
h. Measure the compressed Plastigauge
® width 
“a” on each crankshaft journal.
If the crankshaft-journal-to-crankshaft-jour-
nal-bearing clearance is out of specification, 
select replacement crankshaft journal bear-
ings.



 
 
 








 
 



 
 



 
 







4. Select:
 Crankshaft journal bearings (J
1–J5)
NOTE:
 The numbers “A” stamped into the crankshaft 
web and the numbers “B” stamped into the 
lower crankcase are used to determine the re-
placement crankshaft journal bearing sizes.
J
1–J5 refer to the bearings shown in the crank-
shaft illustration.
 If J
1–J5 are the same, use the same size for all 
of the bearings.
For example, if the crankcase J
1 and crank-
shaft web J
1 numbers are 6 and 2 respective-
ly, then the bearing size for J
1 is:
J1 (crankcase) - J1 (crankshaft web) - 1
=
6 - 2 - 1 = 3 (brown)
 
Bearing color code
1.Blue 2.Black 3.Brown 4.Green 
5.Yellow
J4J3J2J1J5
2 1 1 2 2 1 1 1 1
J1J2J3J4J5A
55554
J1J2J3J4J5B 
						

							CRANKSHAFT
5-70
EAS26200
INSTALLING THE CRANKSHAFT
1. Install:
•Crankshaft journal upper bearings
(into the upper crankcase)
•Crankshaft journal lower bearings
(into the lower crankcase)
NOTE:
•Align the projections “a” on the crankshaft jour-
nal bearings “1” with the notches “b” in the 
crankcases.
•Be sure to install each crankshaft journal bear-
ing in its original place. 
						

							TRANSMISSION
5-71
EAS26240
TRANSMISSION
Removing the transmission, shift drum assembly, and shift forks
Order Job/Parts to remove Q’ty Remarks
CrankcaseSeparate.
Refer to “CRANKCASE” on page 5-55.
1 Drive axle assembly 1
2 Circlip 1
3 Oil seal 1
4 Bearing 1
5 Shift drum retainer 2
6Spring 2
7 Shift fork guide bar 2
8 Shift fork-L 1
9 Shift fork-R 1
10 Shift drum assembly 1
11 Shift fork-C 1
12 Main axle assembly 1
13 Oil pipe 1
14 Bearing 1
E
E
E
E
12
11
7
13
5
676
10 5
498 12
3
15
14
LT
LT
E
E
LT
E
T R..12 Nm (1.2 m • 
kg, 8.7 ft • Ib)
T R..10 Nm (1.0 m • 
kg, 7.2 ft • Ib)
E
New
T R..10 Nm (1.0 m • 
kg, 7.2 ft • Ib)
(3)
New
LS
LS