Yamaha RS90K, Service Manual

Page: 538 / 841

5-60
ENG
CRANKCASE
11. Inspect:
• Crankshaft journal surfaces
• Crankshaft pin surfaces
• Bearing surfaces
Scratches/wear
→
Replace the crankshaft.
12. Measure:
• Crankshaft-journal-to-crankshaft-journal-
bearing clearance
Out of specification
→
Replace the crankshaft
journal bearings.
Measurement steps:
CAUTION:
Do not interchange the crankshaft journal bear-
ings. To obtain the correct crankshaft-journal-
to-crankshaft-journal-bearing clearance and
prevent engine damage, the crankshaft journal
bearings must be installed in their original posi-
tions.
• Clean the crankshaft journal bearings, crank-
shaft journals, and bearing portions of the
crankcase.
• Place the upper crankcase upside down on a
bench.
Crankshaft-journal-to-crankshaft-
journal-bearing clearance:
0.027 ~ 0.045 mm
(0.0011 ~ 0.0018 in)
• Install the crankshaft journal upper bearings 1
and the crankshaft into the upper crankcase.
NOTE:
Align the projections
a
of the crankshaft journal
upper bearings with the notches
b
in the crank-
case.
• Put a piece of Plastigauge
®
2
on each crank-
shaft journal.
NOTE:
Do not put the Plastigauge
®
over the oil hole in the
crankshaft journal.
2