Yamaha YZF-R125 Service Manual: Installing the shift forks and shift drum assembly
1. Install:
- Shift fork-L "1"
- Shift fork-C "2"
- Shift fork-R "3"
- Shift drum assembly "4"
- Springs
- Shift fork guide bar "5"
NOTE:
The embossed marks on the shift forks should face towards the right side of the engine and be in the following sequence: "R", "C", "L".
2. Check:
Transmission
Rough movement 
Repair.
NOTE:
- Apply engine oil to each gear and bearing thoroughly.
- Before assembling the crankcase, make sure that the transmission is in neutral and that the gears turn freely.
Assembling the main axle and drive axle
1. Install:
Toothed washer "1"
Circlip "2"
NOTE:
Be sure to install the circlip so that its sharp
edge "a" is facing away from the toothed washer
and gear.
Be sure the circlip ends ...
Cooling system
...
Other materials:
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.
...
General tightening torque specifications
This chart specifies tightening torques for standard
fasteners with a standard ISO thread pitch.
Tightening torque specifications for special components
or assemblies are provided for each
chapter of this manual. To avoid warpage, tighten
multi-fastener assemblies in a crisscross pattern
and ...
Ignition circuit cut-off system
The ignition circuit cut-off system (comprising
the sidestand switch, clutch
switch and neutral switch) has the following
functions.
It prevents starting when the transmission
is in gear and the sidestand
is up, but the clutch lever is
not pulled.
It prevents starting when the t ...