Yamaha Yzf R1 2007 Manual

CRANKSHAFT
5-71
EAS26030
REMOVING THE CONNECTING RODS AND 
PISTONS
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.
 After removing the connecting rods and con-
necting rod caps, care should be taken not to 
damage the mating surfaces of the connect-
ing rods and connecting rod caps.
2. Remove:
 Cylinder
 Cylinder...

CRANKSHAFT
5-72
NOTE:
Identify the position of each crankshaft journal 
upper bearing so that it can be reinstalled in its 
original place.
EAS24390
CHECKING THE CYLINDER AND PISTON
1. Check:
 Piston wall
 Cylinder wall
Vertical scratches → Rebore or replace the 
cylinder, and replace the piston and piston 
rings as a set.
2. Measure:
 Piston-to-cylinder clearance
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a. Measure cylinder bore “C” with the cylinder 
bore gauge.
NOTE:
Measure cylinder bore “C” by taking...

CRANKSHAFT
5-73
2. Install:
 Piston ring
(into the cylinder)
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 PIN
1. Check:
 Piston pin
Blue discoloration/grooves → Replace the 
piston pin and then check the lubrication 
system.
2....

CRANKSHAFT
5-74
4. Calculate:
 Piston-pin-to-piston-pin-bore clearance
Out of specification → Replace the piston 
pin and piston as a set.
EAS4C81015
CHECKING THE BIG END BEARINGS
1. Measure:
 Crankshaft-pin-to-big-end-bearing clear-
ance
Out of specification → Replace the big end 
bearings.
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The following procedure applies to all of the 
connecting rods.
CAUTION:
ECA14900
Do not interchange the big end bearings 
and connecting rods. To obtain the correct...

CRANKSHAFT
5-75
e. Tighten the connecting rod bolts.
NOTE:
Install by carrying out the following procedures 
in order to assemble in the most suitable con-
dition.
NOTE:
 First, tighten the bolts to 15 Nm (1.5 m·kg, 11 
ft·lb).
 Retighten the bolts to 29.4 Nm (3.0 m·kg, 21 
ft·lb).
f. Replace the connecting rod bolts with new 
ones.
g. Clean the connecting rod bolts.
h. After installing big end bearing, assemble 
the connecting rod and connecting rod cap 
once using a single unit of the connecting...

CRANKSHAFT
5-76
p. After the installation, check that the section 
shown “a” is flush with each other by touch-
ing the surface.
 Side machined face “a”
WARNING
EW2D1008
 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 bearing and restart from step “e”. In 
this case, make sure to replace the...

CRANKSHAFT
5-77
EAS26190
INSTALLING THE CONNECTING ROD AND 
PISTON
The following procedure applies to all of the 
connecting rods and pistons.
1. Install:
 Top ring “1”
 2nd ring “2”
 Oil ring expander “4”
 Upper oil ring rail “3”
 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 clip “4” 
NOTE:
 Apply engine oil onto the piston...

CRANKSHAFT
5-78
7. Install:
 Cylinder gasket “2” 
8. Install:
 Big end bearings
(onto the connecting rods and connecting 
rod caps)
NOTE:
 Align the projections “a” on the big end bear-
ings with the notches “b” in the connecting 
rods and connecting rod caps.
 Be sure to reinstall each big end bearing in 
its original place.
 Make sure that the characters “c” a on both 
the connecting rod and connecting rod cap 
are aligned.
9. Tighten:
 Connecting rod bolts
NOTE:
 Install by carrying out the...

CRANKSHAFT
5-79
11. Install:
 Cylinder assembly “1”
 Connecting rod caps “2”
NOTE:
 Make sure that the “Y” marks “a” on the con-
necting rods face towards the left side of the 
crankshaft.
 Make sure that the characters on both the 
connecting rod and connecting rod cap are 
aligned.
12. Tighten:
 Connecting rod bolts
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CAUTION:
ECA14980
Tighten the connecting rod bolts using the 
plastic-region tightening angle method.
a. Clean the connecting rod bolts.
b. Tighten the...

CRANKSHAFT
5-80
 If they are not flush with each other, 
remove the connecting rod bolt and big 
end bearing and restart from step “9”. In 
this case, make sure to replace the con-
necting rod bolt.
CAUTION:
ECA14680
 Do not use a torque wrench to tighten the 
bolt to the specified angle.
 Tighten the bolt until it is at the specified 
angles.
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EAS4C81016
CHECKING THE CRANKSHAFT
1. Measure:
 Crankshaft runout
Out of specification → Replace the crank-
shaft.
2. Check:
...