Checking The Connecting Rods - Yamaha XSR MTM690 2016 Service Manual

4. Calculate:
• Piston-pin-to-piston-pin-bore clearance
Out of specification → Replace the piston pin
and piston as a set.
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
0.009–0.025 mm (0.0004–0.0010
in)
Limit
0.075 mm (0.0030 in)
EAS30750

CHECKING THE CONNECTING RODS

1. Measure:
• Crankshaft-pin-to-big-end-bearing clearance
Out of specification → Replace the big end
bearings.
Oil clearance
0.027–0.051 mm (0.0011–0.0020
in)
▼ ▼▼▼ ▼ ▼▼▼ ▼ ▼ ▼▼▼ ▼
The following procedure applies to all of the
connecting rods.
ECA13930
NOTICE
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 inside of the connecting rods halves.
b. Install the big end upper bearing into the con-
necting rod and the big end lower bearing into
the connecting rod cap.
▼ ▼▼▼ ▼ ▼ ▼▼▼ ▼ ▼ ▼▼▼ ▼
CONNECTING RODS AND PISTONS
TIP
Align the projections "a" on the big end bearings
with the notches "b" in the connecting rod and
connecting rod cap.
c. Put a piece of Plastigauge® "1" on the crank-
shaft pin.
d. Assemble the connecting rod halves.
ECA18390
NOTICE
Tighten the connecting rod bolts using the
plastic-region tightening angle method. Al-
ways install new bolts.
TIP
• 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.
• After installing the big end bearing, assemble
the connecting rod and connecting rod cap
without installing them onto the crankshaft.
5-75
1