Yamaha 55DEHD - Checking the Crankshaft; Checking the Connecting Rod Big End Side Clearance

Checking the crankshaft
1. Measure the crankshaft journal diameter
a and crankpin diameter b. Replace the
crankshaft if out of specification.
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Crankcase
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1
a
b
68850440
Piston ring end gap a: (reference
data)
Top and 2nd piston ring:
0.40–0.60 mm
(0.0157–0.0236 in)
Measuring point b:
10.0 mm (0.39 in)
Crankshaft journal diameter a:
34.968–34.984 mm
(1.3767–1.3773 in)
Crankpin diameter b:
29.985–30.000 mm
(1.1805–1.1811 in)
a
68850480
b
68850490
2. Measure the crankshaft runout. Replace
the crankshaft if above specification.
Checking the connecting rod big
end side clearance
1. Install the bearing and connecting rod.
2. Measure the connecting rod big end side
clearance a. Replace the connecting rod
or crankshaft or both if out of specifica-
tion.
Crankshaft runout limit c:
0.02 mm (0.0008 in)
cccc
68850500
a
68850470
Connecting rod big end side
clearance a: (reference data)
0.120–0.260 mm
(0.0047–0.0102 in)
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