Yamaha YZF-R1 2012, Service Manual

Page: 329 / 556

CONNECTING RODS AND PISTONS
5-78
4. Calculate:
• Piston-pin-to-piston-pin-bore clearance
Out of specification
→
Replace the piston
pin and piston as a set.
EAS14B1023
CHECKING THE CONNECTING RODS
1. Measure:
• Crankshaft-pin-to-big-end-bearing clear-
ance
Out of specification
→
Replace the big
end bearings.
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
The following procedure applies to all of the
connecting rods.
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 orig-
inal 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
connecting rod and the big end lower bear-
ing into the connecting rod cap.
TIP
Align the projections “a” on the big end bear-
ings with the notches “b” in the connecting rod
and connecting rod cap.
c. Put a piece of Plastigauge® “1” on the
crankshaft pin.
d. Assemble the connecting rod halves.
ECA14B1041
Tighten the connecting rod bolts using the
plastic-region tightening angle method.
Always install new bolts.
TIP
• Replace the connecting rod bolts with new
ones.
• Clean the connecting rod bolts and lubricate
the bolt threads and seats with molybdenum
disulfide oil.
• Make sure that the projection “a” on the con-
necting rod cap faces the same direction as
the “Y” mark “b” on the connecting rod.
Piston-pin-to-piston-pin-bore clearance =
Piston pin bore inside diameter “b” -
Piston pin outside diameter “a”
Piston-pin-to-piston-pin-bore
clearance
0.002–0.022 mm (0.0001–
0.0009 in)
Limit
0.072 mm (0.0028 in)
Crankshaft-pin-to-big-end-bear-
ing clearance
0.034–0.058 mm
(0.0013–0.0023 in)
Limit
0.09 mm (0.0035 in)