Yamaha F6AMH, Service Manual

Page: 294 / 510

CRANKSHAFT, PISTON AND CYLINDER BODY
CHECKING THE CRANKSHAFT-PLAIN
BEARING OIL CLEARANCE
NOTE:
Make sure that the crankshaft is qualified
before initiating the following procedure.
1. Measure:
Crankshaft-plain bearing oil
clearance
Out of specification
Replace the
upper and lower plain bearing as a
set.
NOTE:
Measure the oil clearance at room
temperature (20°C (68°F))
Measuring steps:
CAUTION:
Install the plain bearings in their original
positions. Incorrect oil clearance
measurements can lead to engine damage.
(1)Clean the plain bearings, main journal
of the crankshaft, and plain bearing
portion of the cylinder body and
crankcase.
(2)Place the cylinder body 2 upside
down on a bench.
(3)Install the half of the plain bearings
1
to the cylinder body
2
and the
crankcase 3 .
NOTE:
Set the part of the plain bearing with the
tab in tab groove
a
, and insert the part
with no tab in corner
b
.
(4)Install the crankshaft 4 to the cylinder
body
2
.
(5)Put a piece of Plastigauge® on each
main journal in parallel to the
crankshaft.
NOTE:
Do not put a Plastigauge® over the oil hole
in the main journal of the crankshaft.
Crankshaft-plain bearing oil
clearance:
0.011 - 0.039 mm
(0.0004 - 0.0015 in)
5-57