Yamaha YZF-R1, Service Manual

Page: 365 / 808

CONNECTING RODS AND PISTONS
5-82
EAS30749
CHECKING THE PISTON PIN
The following procedure applies to all of the pis-
ton pins.
1. Measure:
• Piston pin outside diameter “a”
Out of specification
→
Replace the piston pin.
2. Measure:
• Piston pin bore inside diameter “b”
Out of specification
→
Replace the piston.
3. Calculate:
• Piston-pin-to-piston-pin-bore clearance
Out of specification
→
Replace the piston pin
and piston as a set.
EAS30750
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.
NOTICE
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 connecting rods with oil
cleaner.
TIP
When cleaning the connecting rod, clean the
bearing surface “a” of the connecting rod bolt
and threads “b”.
b. Upper of cylinder
Piston pin outside diameter
16.991–17.000 mm (0.6689–
0.6693 in)
Limit
16.971 mm (0.6681 in)
Piston pin bore inside diameter
17.002–17.013 mm (0.6694–
0.6698 in)
Limit
17.043 mm (0.6710 in)
a
b
G0 8 9004
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)
Oil clearance
0.033–0.057 mm (0.0013–0.0022
in)
b
G0 8 9005