Yamaha Fz6n Manual

							5-81
CONNECTING RODS AND PISTONSENG
NOTE:
24.5 Nm (2.5 m
kg, 17.7 ft
lb)
CAUTION:
NOTE:
NOTE: 7. Tighten:
Install by carrying out the following procedures
in order to assemble in the most suitable condi-
tion.

connecting rod bolts.
a. Replace the connecting rod bolts with new
oncs.
Tighten the connecting rod bolts using the
plastic-region tightening angle method.
Always install new bolts.
b. Clean the connecting rod bolts.
c. After installing the big end bearing, assemble
the connecting rod and connecting rod cap
once using a single unit of the connecting
rod.
d. Tighten the connecting rod bolt while check-
ing that the sections shown 
a and b are
flush with each other by touching the surface.

Side machined face 
a

Thrusting faces (4 places at front and rear)
b
To install the big end bearing, care should be
taken not to install it at an angle and the position
should not be out of alignment.
e. Loosen the connecting rod bolt, remove the
connecting rod and connecting rod cap and
install these parts to the crankshaft with the
big end bearing kept in the current condition.
8. Install:

connecting rod assembly
(into the cylinder and onto the crankshaft pin)

Be sure to reinstall each big end bearing in its
original place.

While compressing the piston rings with one
hand, install the connecting rod assembly into
the cylinder with the other hand.

Make sure that the “Y” marks 
a on the con-
necting rods face towards the left side of the
crankshaft. 
						

							5-82
CONNECTING RODS AND PISTONSENG
15 Nm (1.5 m
kg, 11 ft
lb) + 120
WARNING
CAUTION:
9. Tighten:

connecting rod bolts
a. Clean the connecting rod bolts.
b. Tighten the connecting rod bolts.
c. Put a mark 
1 on the corner of the connecting
rod bolt 
2 and the connecting rod 3.
d. Tighten the bolt further to reach the specified
angle (120).
e. After the installation, check that the section
shown 
a is flush with each other by touching
the surface.

Side machined face 
a

When the bolt is 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.

If they are not flush with each other, remove
the connecting rod bolt and big end bear-
ing and restart from step “7”. In this case,
make sure to replace the connecting rod
bolt.

Do not use a torque wrench to tighten the
nut to the specified angle.

Tighten the bolt until it is at the specified
angles. 
						

							5-83
Order Job / Part Q’ty Remarks
1
2
3Removing the crankshaft
Crankcase
Connecting rod caps
Crankshaft
Crankshaft journal lower bearing
Crankshaft journal upper bearing1
5
5Remove the parts in the order listed.
Separate.
Refer to “CRANKCASE”.
Refer to “CONNECTING RODS AND 
PISTONS”.
For installation, reverse the removal 
procedure.
CRANKSHAFTENG
EAS00381
CRANKSHAFT 
						

							5-84
CRANKSHAFTENG
CAUTION:
EAS00395
CHECKING THE CRANKSHAFT
1. Measure:

crankshaft runout
Out of specification 
 Replace the crank-
shaft.
Crankshaft runout
Less than 0.03 mm (0.0012 in)
2. Check:

crankshaft journal surfaces

crankshaft pin surfaces

bearing surfaces
Scratches / wear 
 Replace the crankshaft.
CHECKING THE CRANKSHAFT JOURNAL
BEARINGS
1. Measure:

crankshaft-journal-to-crankshaft-journal-
bearing clearance
Out of specification 
 Replace the crank-
shaft journal bearings.
Crankshaft-journal-to-crankshaft-
journal-bearing clearance
0.034 
 0.058 mm 
(0.0013 
 0.0023 in)
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,
crankshaft journals, and bearing portions of
the crankcase.
b. Place the upper crankcase upside down on a
bench. 
						

							5-85
CRANKSHAFTENG
NOTE:
NOTE:
NOTE:
NOTE: c. Install the crankshaft journal upper bearings
1 and the crankshaft into the upper crank-
case.
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
 2 on each
crankshaft journal.
Do not put the Plastigauge
 over the oil hole in
the crankshaft journal.
e. Install the crankshaft journal lower bearings
1 into the lower crankcase and assemble
the crankcase halves.

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.
Crankcase bolt
Bolt 
1 
 10
1st: 12 Nm (1.2 m
kg, 8.7 ft
lb)
2nd: 25 Nm (2.5 m
kg, 18 ft
lb)
*3rd: 27 Nm (2.7 m
kg, 20 ft
lb)
Bolt 
11, 12
24 Nm (2.4 m
kg, 17 ft
lb)
Bolt 
13, 14
14 Nm (1.4 m
kg, 1.0 ft
lb)
Bolt 
15 
 27
12 Nm (1.2 m
kg, 8.7 ft
lb)
* Loosen the bolts following the tightening order
and then tighten to specification torque.
Lubricate the crankcase bolt threads with en-
gine oil.
Refer to “CRANKCASE”. 
						

							5-86
CRANKSHAFTENG
NOTE:
g. Remove the lower crankcase and the crank-
shaft journal lower bearings.
h. Measure the compressed Plastigauge

width c on each crankshaft journal.
If the crankshaft-journal-to-crankshaft-jour-
nal-bearing clearance is out of specification,
select replacement crankshaft journal bear-
ings.
2. Select:

crankshaft journal bearings (J1 
 J5)

The numbers 
A stamped into the crankshaft
web and the numbers 
1 stamped into the low-
er crankcase are used to determine the re-
placement crankshaft journal bearing sizes.

“J1 
 J5” refer to the bearings shown in the
crankshaft illustration.

If “J1 
 J5” are the same, use the same size
for all of the bearings.

If the size is the same for all “J
1 to J5” one digit
for that size is indicated. (Crankcase side only)
For example, if the crankcase “J
1” and crank-
shaft web “J
1” numbers are “6” and “2” respec-
tively, then the bearing size for “J1” is:
“J
1” (crankcase) – “J1”
(crankshaft web) – 1 =
6 – 2 – 1 = 3 (brown)
CRANKSHAFT JOURNAL BEARING
COLOR CODE
0White
1Black
2Brown
3Green
4Yellow 
						

							5-87
CRANKSHAFTENG
NOTE:
EAS00407
INSTALLING THE CRANKSHAFT
1. Install:

crankshaft journal upper bearings 
1
(into the upper crankcase)

Align the projections 
a on the crankshaft jour-
nal upper bearings with the notches 
b in the
upper crankcase.

Be sure to install each crankshaft journal up-
per bearing in its original place.
2. Install:

crankshaft
3. Install:

crankcase (lower)
Refer to “CRANKCASE”. 
						

							5-88
Order Job / Part Q’ty Remarks
1
2
3
4
5
6
7
8
9
10
11Removing the transmission, shift 
drum assembly, and shift forks
Crankcase lower
Drive axle assembly
Circlip
Oil seal
Bearing
Shift drum retainer
Shift fork guide bar
Spring
Shift fork “L”
Shift fork “R”
Shift drum assembly
Shift fork “C”1
1
1
1
1
2
4
1
1
1
1Remove the part in the order listed.
Separate.
Refer to “CRANKCASE”.
12 Nm (1.2 m
kg, 8.7 ft
lb)
12 Nm (1.2 m
kg, 8.7 ft
lb)
10 Nm (1.0 m
kg, 7.2 ft
lb)10 Nm (1.0 m
kg, 7.2 ft
lb)
TRANSMISSIONENG
EAS00419
TRANSMISSION
TRANSMISSION, SHIFT DRUM ASSEMBLY AND SHIFT FORKS 
						

							5-89
TRANSMISSIONENG
Order Job / Part Q’ty Remarks
12
13
14
15
16Main axle assembly
Oil pipe
Oil baffle plate
Thrust plate
Washer1
1
1
1
1
For installation, reverse the removal 
procedure.
12 Nm (1.2 m
kg, 8.7 ft
lb)
12 Nm (1.2 m
kg, 8.7 ft
lb)
10 Nm (1.0 m
kg, 7.2 ft
lb)10 Nm (1.0 m
kg, 7.2 ft
lb) 
						

							5-90
Order Job / Part Q’ty Remarks
Disassembling the main axle 
assembly
Bearing
2nd pinion gear
Toothed lock washer
Toothed lock washer retainer
6th pinion gear
Collar
Washer
Circlip
3rd pinion gear
Circlip
Washer
5th pinion gear
Collar
Main axle1
1
1
1
1
1
1
1
1
1
1
1
1
1Disassemble the parts in the order listed.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
TRANSMISSIONENG