Yamaha YZF-R125 Service Manual: 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 progressive stages until the specified
tightening torque is reached. Unless otherwise
specified, tightening torque specifications require
clean, dry threads. Components should be
at room temperature. 
A. Distance between flats
B. Outside thread diameter
Engine tightening torques
Cylinder head tightening sequence:
Generator cover tightening sequence:
Clutch cover tightening sequence:
Crankcase tightening sequence:
A. Left crankcase
B. Right crankcase ...
Other materials:
Installing the relay arm
1. Lubricate:
Spacers
Bearings
Oil seals
Bolts (unthreaded shaft portion only)
2. Install:
Bearing "1"
(to the relay arm)
Oil seal "2"
(to the relay arm)
3. Rear shock absorber assembly
4. Relay arm
5. Connecting arm
A. Left side
B. Right side ...
Ecu self-diagnostic function
The ECU is equipped with a self-diagnostic function in order to ensure that
the fuel injection system is
operating normally. If this function detects a malfunction in the system, it
immediately operates the engine
under substitute characteristics and illuminates the engine trouble warning
li ...
Checking the drive sprocket
1. Check:
Drive sprocket
More than 1/4 tooth "a" wear
Replace the
drive chain sprockets as a set.
Bent teeth Replace the drive
chain sprockets
as a set.
b. Correct
1. Drive chain roller
2. Drive chain sprocket
Checking the rear wheel sprocket
Refer to "CHECKING AND R ...