Checking The Crankshaft And Connecting Rod - Yamaha YP400T Service Manual

CRANKSHAFT
EAS00394
CHECKING THE CRANKSHAFT AND
CONNECTING ROD
1. Measure:
• crankshaft runout
Out of specification → Replace the crank-
shaft, bearing or both.
NOTE:
_
Turn the crankshaft slowly.
Maximum crankshaft runout
0.030 mm (0.0012 in)
2. Check:
• crankshaft journal surfaces
Scratches/wear → Replace the crankshaft.
3. Measure:
• big end side clearance
Out of specification → Replace the big end
bearing, crankshaft pin, or connecting rod.
Big end side clearance
0.350 ~ 0.850 mm
(0.0138 ~ 0.0335 in)
4. Measure:
• crankshaft-journal-to-crankshaft-journal-
bearing clearance
Out of specification → Replace the crank-
shaft journal bearings as a set.
Crankshaft-journal-to-crankshaft-
journal-bearing clearance
0.030 ~ 0.077 mm
(0.0012 ~ 0.0030 in)
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The following procedure applies to each
crankshaft journal and its corresponding
journal bearing.
a. Clean the surface of the journal and the
journal bearing.
b. Check the bearing surface. If the bearing
surface is worn or scratched, replace the
bearings as a set.
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ENG
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