Checking The Big End Bearings - Yamaha YZF-R7 Owner's Service Manual

CONNECTING RODS AND PISTONS
4 - 68
4. Calculate:
• piston pin-to-piston pin bore clearance
Out of specification
ton pin.
Piston pin-to-piston pin bore clearance =
Piston pin bore diameter (in the
piston) –
Piston pin outside diameter
Piston pin-to-piston pin bore
clearance
0.004 ~ 0.020 mm
(0.00016 ~ 0.00079 in)
<Limit>: 0.070 mm (0.0028 in)

CHECKING THE BIG END BEARINGS

1. Measure:
• crankshaft pin-to-big
clearance
Out of specification
end bearings.
Crankshaft pin-to-big end
bearing clearance
0.058 ~ 0.078 mm
(0.0023 ~ 0.0031 in)
The following procedure applies to all of
the connecting rods.
CAUTION:
ACHTUNG:
Do not interchange the big end bearings
and connecting rods. To obtain the cor-
rect crankshaft pin-to-big end bearing
clearance and prevent engine damage,
the big end bearings must be installed
in their original positions.
a. Clean the big end bearings, crank-
shaft pins, and bearing portions of
the connecting rods.
b. Install the big end upper bearing into
the connecting rod and the big end
lower bearing into the connecting rod
cap.
NOTE:
Align the projections a on the big end
bearings with the notches b in the con-
necting rod and connecting rod cap.
ENG
Replace the pis-
end bearing
Replace the big