Yamaha YZF-R125 Service Manual: Checking the timing chain and timing chain guide
1. Check:
- Timing chain
Damage/stiffness
Replace the
timing chain and camshaft sprocket as a set.
2. Check:
Timing chain guide (intake side)
Damage/wear Replace.
Checking the oil strainer
1. Check:
Oil strainer
Damage Replace.
Contaminants Clean with solvent.
Checking the crankcase
1. Thoroughly wash the crankcase halves in a
mild solvent.
2. Thoroughly clean all the gasket surfaces and
crankcase mating surfaces.
3. Check:
Crankcase
Cracks/damage Replace.
Oil de ...
Checking the bearings and oil seal
1. Check:
Bearings
Clean and lubricate the bearings, and then
rotate the inner race with your finger.
Rough movement Replace.
Oil seal
Damage/wear Replace.
...
Other materials:
Checking the brake fluid level
1. Stand the vehicle on a level surface.
NOTE:
Place the vehicle on a suitable stand.
Make sure the vehicle is upright.
2. Check:
Brake fluid level
Below the minimum level mark "a" → Add the
recommended brake fluid to the proper level.
A. Front brake
B. Rear brake
WA ...
Checking the rocker arms and rocker arm shafts
The following procedure applies to all of the
rocker arms and rocker arm shafts.
1. Check:
Rocker arm
Damage/wear Replace.
2. Check:
Rocker arm shaft
Blue discoloration/excessive wear/pitting/
scratches Replace or
check the lubrication
system.
3. Measure:
Rocke ...
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&nbs ...