Removing The Crankshaft; Checking The Crankshaft; Installing The Crankshaft - Yamaha YZ125 2022 Owner's Service Manual

EAM30491

REMOVING THE CRANKSHAFT

1. Remove:
• Crankshaft "1"
(with the crankcase separating tool "2")
Crankcase separating tool
90890-01135
Crankcase separator
YU-01135-B
TIP
Make appropriate bolts "3" as shown available
by yourself and attach the tool with them.
ECA22290
NOTICE
Do not use a hammer to drive out the crank-
shaft.
EAM30492

CHECKING THE CRANKSHAFT

1. Measure:
• Crankshaft runout "a"
Out of specification  Replace the crank-
shaft, bearing or both.
TIP
Turn the crankshaft slowly.
Runout limit
0.030 mm (0.0012 in)
a
2. Measure:
• Crank assembly width "a"
Out of specification  Replace the crank-
a
5-44
shaft.
Crank assembly width
55.90–55.95 mm (2.201–2.203 in)
EAM30493

INSTALLING THE CRANKSHAFT

1. Install:
• Crankshaft assembly "1"
TIP
Install the crankshaft assembly with the crank-
shaft installer pot "2", crankshaft installer bolt "3",
and adapter (M12) "4".
Crankshaft installer pot
90890-01274
Installing pot
YU-90058
Crankshaft installer bolt
90890-01275
Bolt
YU-90060
Adapter (M12)
90890-01278
Adapter #3
YU-90063
ECA26470
NOTICE
In order to prevent the crankshaft seizure,
apply molybdenum disulfide grease.
ECA23810
NOTICE
Do not use a hammer to drive in the crank-
shaft.
TIP
• Hold the connecting rod at top dead center
(TDC) with one hand while turning the nut of
the crankshaft installer bolt with the other. Turn
the crankshaft installer bolt until the crankshaft
assembly bottoms against the bearing.
• Before installing the crankshaft, clean the con-
tacting surface of crankcase.
• Apply the lithium-soap-based grease on the oil
CRANKSHAFT