Yamaha YZ250F Owner's Service Manual page 127

CAMSHAFTS
• Fit the timing chain 3 onto both camshaft
sprockets and install the camshafts on the
cylinder head.
NOTE:
The camshafts should be installed onto the
cylinder head so that the punch mark c on
the exhaust camshaft and the punch mark
d on the intake camshaft must align with
the cylinder head surface, as shown in the
illustration.
CAUTION:
Do not turn the crankshaft during the
camshaft
improper valve timing will result.
• Install the clips, camshaft caps 4 and
bolts (camshaft cap) 5.
Bolt (camshaft cap):
10 Nm (1.0 m • kg, 7.2 ft • lb)
NOTE:
• Before removing the clips, cover the cylin-
der head with a clean rag to prevent the
clips from into the cylinder head cavity.
• Apply the engine oil on the thread and
contact surface of the bolts (camshaft
cap).
• Tighten the bolts (camshaft cap) in a criss-
cross pattern.
CAUTION:
The bolts (camshaft cap) must be tight-
ened evenly, or damage to the cylinder
head, camshaft caps, and camshaft will
result.
2. Install:
• Timing chain tensioner
Installation steps:
• While pressing the tensioner rod lightly
with fingers, use a thin screwdriver and
wind the tensioner rod up fully clockwise.
4 - 27
ENG
installation. Damage or