Ignition Timing Check - Yamaha YZ125(N)/LC Owner's Service Manual

IGNITION TIMING CHECK

EC372051
IGNITION TIMING CHECK
1. Remove:
9 Cylinder head
Refer to "CYLINDER HEAD, CYLINDER
AND PISTON" section in the CHAPTER 4.
9 Crankcase cover (left)
2. Attach:
9 Dial gauge 1
9 Dial gauge stand 2
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.
6. Check:
9 Ignition timing
Punch mark a on rotor should be aligned
with punch mark b on stator.
Not aligned
3-39
INSP
ADJ
Dial gauge:
YU-3097/90890-01252
Stand:
YU-1256
Ignition timing (B.T.D.C.):
0.52 mm (0.020 in)
Adjust.