Ignition Timing Check - Yamaha YZ125N1 Service Manual

IGNITION TIMING CHECK

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