1999 YAMAHA YZF-R7 oil

4 - 61
ENG

CRANKCASE
EB412743
ASSEMBLING THE CRANKCASE
1. Lubricate:
• crankshaft journal bearings
(with the recommended lubricant)
Recommended lubricant
Engine oil
2. Apply:
• sealant
(onto the crankcase mating surfaces)
NOTE:

Do not allow any sealant to come into
contact with the oil gallery or crankshaft
journal bearings. Do not apply sealant to
within 2 ~ 3 mm (0.08 ~ 0.12 in) of the
crankshaft journal bearings.
3. Install:
• dowel pins
1

Yamaha bond No. 1215
90890-85505
4. Install:
• crankshaft journal lower bearings
(into the lower crankcase)
NOTE:

• Align the projections
a
on the crank-
shaft journal lower bearings with the
notches
b
in the lower crankcase.
• Install each crankshaft journal lower
bearing in its original place.
5. Set the shift drum assembly and trans-
mission gears in the neutral position.

4 - 62
ENG

CRANKCASE
6. Install:
• lower crankcase
1
(onto the upper crankcase
2
)
ACHTUNG:CAUTION:

Before tightening the crankcase bolts,
make sure that the transmission gears
shift correctly when the shift drum
assembly is turned by hand.
7. Install:
• crankcase bolts
NOTE:

• Lubricate the bolt threads with engine
oil.
• Install a washer on bolts
1
~
@
.
• Tighten the bolts in the tightening
sequence cast on the crankcase.
M9
´
105 mm bolts:
1
~
@

M8
´
60 mm bolt:
K
,
L
M6
´
70 mm bolts:
G
,
I
,
O
,
Q

M6
´
64 mm bolts:
F
,
N

M6
´
60 mm bolt:
M

M6
´
55 mm bolts:
A
~
E

M6
´
50 mm bolt:
H

M6
´
45 mm bolts:
J
,
P
,
R

T R..

Bolt
1
~
@

32 Nm (3.2 m • kg, 23 ft • lb)
Bolt
A
~
E
,
G
~
J
,
M
,
O
~
R
12 Nm (1.2 m • kg, 8.7 ft • lb)
Bolt
F
,
N

14 Nm (1.4 m • kg, 10 ft • lb)
Bolt K, L
24 Nm (2.4 m • kg, 17 ft • lb)

ENG
4 - 63
CONNECTING RODS AND PISTONS
EB404001
CONNECTING RODS AND PISTONS
Order Job/Part Q’ty Remarks
Removing the connecting rods and
pistonsRemove the parts in the order listed.
Crankcase Separate.
Refer to “CRANKCASE”.
1 Connecting rod cap 4
2 Big end lower bearing 4
3 Piston pin clip 8
4 Piston pin 4
5 Piston 4
6 Connecting rod 4
7 Big end upper bearing 4
8 Top ring 4
9 2nd ring 4
10 Oil ring 4
For installation, reverse the removal
procedure.

4 - 64
ENGCONNECTING RODS AND PISTONS
EB412131
REMOVING THE CONNECTING RODS AND
PISTONS
The following procedure applies to all of
the connecting rods and pistons.
1. Remove:
• connecting rod cap
• big end bearings
NOTE:
Identify the position of each big end
bearing so that it can be reinstalled in its
original place.
2. Remove:
• piston pin clips 1
• piston pin 2
• piston 3
• connecting rod 4
ACHTUNG:CAUTION:
Do not use a hammer to drive the piston
pin out.
NOTE:
• For reference during installation, put
identification marks on the piston
crown.
• Before removing the piston pin, deburr
the piston pin clip groove and the pis-
ton pin bore area in the piston. If both
areas are deburred and the piston pin
is still difficult to remove, remove it
with the piston pin puller 4.
Piston pin puller
90890-01304
3. Remove:
• top ring
• 2nd ring
• oil ring
NOTE:
To remove a piston ring, open the end
gap with your fingers and lift the other
side of the ring over the piston crown.

4 - 67
ENGCONNECTING RODS AND PISTONS
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 excessive, replace all three piston
rings.
Piston ring end gap
Top ring
0.15 ~ 0.25 mm
(0.006 ~ 0.010 in)
: 0.50 mm (0.020 in)
2nd ring
0.25 ~ 0.35 mm
(0.009 ~ 0.014 in)
: 0.70 mm (0.028 in)
Oil ring
0.1 ~ 0.3 mm
(0.004 ~ 0.012 in)
EB404421
CHECKING THE PISTON PINS
The following procedure applies to all of
the piston pins.
1. Check:
• piston pin
Blue discoloration/grooves ® Replace
the piston pin and then check the lubri-
cation system.
2. Measure:
• piston pin outside diameter a
Out of specification ® Replace the pis-
ton pin.
Piston pin outside diameter
16.995 ~ 17.000 mm
(0.6691 ~ 0.6693 in)
: 16.975 mm (0.6683 in)
3. Measure:
• piston pin bore diameter (in the piston)
Out of specification ® Replace the pis-
ton pin.
Piston pin bore diameter
(in the piston)
17.004 ~ 17.015 mm
(0.6694 ~ 0.6699 in)
: 17.045 mm (0.6711 in)

4 - 70
ENGCONNECTING RODS AND PISTONS
2. Select:
• big end bearings (“P
1”~ “P4”)
NOTE:
• The numbers stamped into the crank-
shaft 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 crankshaft illustration.
t t t t t t t t t t t t t t t t t t t t t t t t t t t
For example, if the connecting rod
“P
1” and the crankshaft web “P1” num-
bers are “9” and “3” respectively, then
the bearing size for “P
1” is:
s s s s s s s s s s s s s s s s s s s s s s s s s s s
“P1” (connecting rod) – “P1” (crank-
shaft) =
9 – 3 = 6
BIG END BEARING COLOR CODE
2 blue
3
black
4
5
brown
6
7
green
8
9 yellow
EB404704
INSTALLING THE PISTONS AND
CONNECTING RODS
The following procedure applies to all of
the pistons and cylinders.
1. Install:
• top ring
• 2nd ring
• oil ring
NOTE:
Be sure to install the piston rings so that
the manufacturer’s marks or numbers
face up.

4 - 71
ENGCONNECTING RODS AND PISTONS
2. Install:
• piston 1
(onto the respective connecting rod 2)
• piston pin 3
• piston pin clip 4
NOTE:
• Apply engine oil onto the piston pin.
• Make sure that the “Y” mark a on the
connecting rod faces left when the
arrow mark b on the piston is pointing
up. Refer to the illustration.
• Reinstall each piston into its original
cylinder (numbering order starting
from the left: #1 to #4).
Piston head
New
3. Offset:
• piston ring end gaps
aTop ring
bLower oil ring rail
cUpper oil ring rail
d2nd ring
Intake side
4. Lubricate:
• piston
• piston rings
• cylinder
(with the recommended lubricant)
5. Lubricate:
• bolt threads
• nut seats
(with the recommended lubricant)
ACHTUNG:CAUTION:
MOLYKOTEâ “G-n” paste is a special
grease, which should not be applied to
any part other than those specified.
Recommended lubricant
Engine oil
Recommended lubricant
MOLYKOTE® G-n paste

4 - 72
ENGCONNECTING RODS AND PISTONS
NOTE:
Apply only a thin even layer of
MOLYKOTE‚ “G-n” paste, otherwise the
correct tightening torque cannot be
achieved.
6. Lubricate:
• crankshaft pins
• big end bearings
• connecting rod big end inner surface
(with the recommended lubricant)
Recommended lubricant
Engine oil
7. Install:
• big end bearings
• connecting rod assembly
(into the cylinder and onto the crank-
shaft pin)
• connecting rod cap
(onto the connecting rod)
NOTE:
• Align the projections on the big end
bearings with the notches in the con-
necting rods and connecting rod caps.
• Be sure to reinstall each big end bear-
ing in its original place.
• While compressing the piston rings
with piston ring compressor 1, install
the connecting rod assembly into the
cylinder with the other hand.
• Make sure that the “Y” marks a on the
connecting rods face towards the left
side of the crankshaft.
• Make sure that the characters b on
both the connecting rod and connect-
ing rod cap are aligned.
8. Align:
• bolt heads
(with the connecting rods)
Piston ring compressor:
90890-05158
1