Yamaha VMX12 2001 Service Manual page 210

CONNECTING RODS AND PISTONS
4 - 80
2. Measure:
• piston pin outside diameter a
Out of specification → Replace the piston
pin.
Piston pin outside diameter
18.991 ~ 19.000 mm
3. Calculate:
• piston-pin-to-piston clearance
Out of specification → Replace the piston
pin.
Piston-pin-to-piston clearance =
Piston pin bore size b –
Piston pin outside diameter a
Piston-pin-to-piston clearance
0.004 ~ 0.024 mm
<Limit>: 0.072 mm
4. Measure:
• crankshaft-pin-to-big-end-bearing clear-
ance
Out of specification → Replace the big end
bearings.
Crankshaft-pin-to-big-end-bear-
ing clearance
0.021 ~ 0.039 mm
The following procedure applies to all of the
connecting rods.
CAUTION:
@
Do not interchange the big end bearings
and connecting rods. To obtain the correct
crankshaft-pin-to-big-end-bearing
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 rod halves.
b. Install the big end upper bearing into the
connecting rod and the big end lower bear-
ing into the connecting rod cap.
ENG
clear-