Yamaha YZ125 2022 Owner's Service Manual page 89

EAM20137
ELECTRICAL SYSTEM
EAM30255
CHECKING THE IGNITION TIMING
1. Remove:
• Fuel tank
Refer to "FUEL TANK" on page 7-1.
• Spark plug
• Crankcase cover (left)
2. Attach:
• Dial gauge "1"
• Spark plug hole dial stand "2"
Dial gauge & stand set
90890-01252
Dial gauge set
YU-03097-B
3. Rotate the magneto rotor "1" until the piston
reaches top dead center (TDC). When this
happens, the needle on the dial gauge will
stop and reverse directions even though the
rotor is being turned in the same direction.
4. Set the dial gauge to zero at TDC.
5. From TDC, rotate the rotor clockwise until the
dial gauge indicates that the piston is at a
specified distance from TDC.
Ignition timing (B.T.D.C.)
0.50 mm (0.02 in)
6. Check:
• Ignition timing
ELECTRICAL SYSTEM
Punch mark "a" on rotor should be aligned
with punch mark "b" on stator.
Not aligned  Adjust.
7. Adjust:
• Ignition timing
a. Loosen the stator coil screws "1".
b. Align the punch mark on the rotor with
punch mark on the stator by moving the
stator "2".
c. Tighten the stator coil screws.
Stator coil screw
7 N·m (0.7 kgf·m, 5.2 lb·ft)
3-25