Yamaha F50A - Selecting the Connecting Rod Big End Bearing

POWR
Power unit
5-63
62Y3A11
4. When installing the main bearing, insert
the projection of the main bearing into
the slot on the cylinder body.
CAUTION:
Remove any small metal particles and oil
from the contact surfaces of the cylinder
body and the main bearing.
5. Measure the main journal oil clearance
with a piece of Plastigauge (PG-1).
6. If the oil clearance is below specification,
check the main bearing color and clean
the contact surface of the cylinder body
and the main bearing, and then check
the main journal oil clearance again.
7. If the oil clearance is over specification,
install an oversized main bearing, and
then check the main journal oil clearance
again.
Selecting the connecting rod big end
bearing
1. When replacing the connecting rod bear-
ing, select the suitable connecting rod
bearing as follows.
2. Check the crank pin mark on the crank-
shaft
1
and the connecting rod cap mark
or painted color on the connecting rod
2
.
3. Select the suitable color
a
for the con-
necting rod bearing from the table.
4. When installing the connecting rod bear-
ing, insert the projection of the connect-
ing rod bearing into the slot on the
connecting rod.
CAUTION:
Remove any small metal particles and oil
from the contact surfaces of the connect-
ing rod and the connecting rod bearing.
5. Measure the crank pin oil clearance with
a piece of Plastigauge (PG-1).
Crankshaft main journal oil clearance:
0.012–0.036 mm (0.0005–0.0014 in)
Connecting
rod cap
mark/color
Crank pin
mark
Bearing
color
I
/Red A Yellow
I
/Red B
Red
II
/Blue A
II
/Blue B
Pink
III
/Yellow A
III
/Yellow B Green
Crank pin oil clearance:
0.016–0.040 mm (0.0006–0.0015 in)