Yamaha YZF-R125 Service Manual: Checking the crankshaft
1. Measure:
- Crankshaft runout
Out of specification
Replace
the crankshaft, bearing or both.
NOTE:
Turn the crankshaft slowly.
2. Measure:
- Big end side clearance
Out of specification
Replace
the crankshaft.
3. Measure:
- Crankshaft width
Out of specification
Replace the crankshaft.
3. Measure:
- Crankshaft width
Out of specification Replace the crankshaft.
4. Check:
- Crankshaft sprocket
Damage/wear
Replace the
crankshaft. - Bearing
Cracks/damage/wear
Replace the
crankshaft.
5. Check:
- Crankshaft journal
Scratches/wear
Replace the
crankshaft. - Crankshaft journal oil passage
Obstruction
Blow out with
compressed air.
Removing the crankshaft
1. Remove:
Crankshaft "1"
NOTE:
Remove the crankshaft with the crankcase
separating tool "2".
Make sure the crankcase separating tool is
centered over the crankshaft.
CAUTIO ...
Installing the crankshaft
1. Install:
Crankshaft "1"
NOTE:
Install the crankshaft with the crankshaft installer
pot "2", crankshaft installer bolt "3", adapter
(M12) "4" and spacer (crankshaft installer) "5".
...
Other materials:
Assembling the crankcase
1. Thoroughly clean all the gasket mating surfaces
and crankcase mating surfaces.
2. Apply:
Sealant
(onto the crankcase mating surfaces)
NOTE:
Do not allow any sealant to come into contact
with the oil gallery.
3. Install:
Right crankcase
NOTE:
Turn the shift drum segment ...
Checking the connections
Check the leads, couplers, and connectors for
stains, rust, moisture, etc.
1. Disconnect:
Lead
Coupler
Connector
2. Check:
Lead
Coupler
Connector
Moisture → Dry with an air blower.
Rust/stains → Connect and disconnect several
times.
3. Check:
All co ...
Checking the starter motor
1. Check:
Commutator
Dirt Clean with 600 grit
sandpaper.
2. Measure:
Commutator diameter "a"
Out of specification Replace
the starter
motor.
3. Measure:
Mica undercut "a"
Out of specification Scrape
the mica to the
proper measurement with a hacksaw blade
...