Yamaha YZF-R125 Service Manual: 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 delivery passages
Obstruction
Blow out with
compressed air.
Separating the crankcase
1. Remove:
Crankcase bolts
NOTE:
Loosen each bolt 1/4 of a turn at a time, in stages
and in the proper sequence as shown.
A. Right crankcase
B. Left crankcase
2. Turn:
Shift drum s ...
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 stra ...
Other materials:
Adjusting the engine idling speed
The engine idling speed must be
checked and, if necessary, adjusted as
follows at the intervals specified in the
periodic maintenance and lubrication
chart.
The engine should be warm before
making this adjustment.
Remove panel A.
Check the engine idling speed
and, if necessary, ...
Intake air pressure sensor
1. Check:
Intake air pressure sensor output voltage
Out of specification Replace the throttle
body.
a. Connect the pocket tester (DC 20 V) to the
throttle body sensor assembly coupler as
shown.
Positive tester probe
pink/white "1"
Negative tester probe
gray/black "2"
...
Introduction
WARNINGDisc brake components rarely require
disassembly.
Therefore, always follow these preventive
measures:
Never disassemble brake components unless
absolutely necessary.
If any connection on the hydraulic brake
system is disconnected, the entire brake
sy ...