Yamaha YZ250F(W), Руководство по эксплуатации для владельца

Страница: 204 / 676

3 - 19
INSP
ADJ
VALVE CLEARANCE INSPECTION AND ADJUSTMENT
2. Remove:
• Spark plug
• Cylinder head cover
Refer to “CAMSHAFTS” section in the
CHAPTER 4.
3. Remove:
• Timing mark accessing screw
1
• Crankshaft end accessing screw
2
• O-ring
4. Check:
• Valve clearance
Out of specification
→
Adjust.
Valve clearance (cold):
Intake valve:
0.10 ~ 0.15 mm
(0.0039 ~ 0.0059 in)
Exhaust valve:
0.17 ~ 0.22 mm
(0.0067 ~ 0.0087 in)
Checking steps:
• Turn the crankshaft counterclockwise with
a wrench.
• Align the T.D.C. mark
a
on the rotor with
the align mark
b
on the crankcase cover
when piston is at T.D.C. on compression
stroke.
NOTE:
In order to be sure that the piston is at Top
Dead Center, the punch mark
c
on the
exhaust camshaft and the punch mark
d
on
the intake camshaft must align with the cyl-
inder head surface, as shown in the illustra-
tion.