Yamaha YZ450F(D) Owner's Service Manual page 93

c. Fit the timing chain "3" onto both
camshaft sprockets and install the
camshafts on the cylinder head.
Make sure that the alignment mark
"c" on the exhaust camshaft sprocket
and the alignment mark "d" on the in-
take camshaft sprocket are aligned
with the edge of the cylinder head.
Do not turn the crankshaft during
the camshaft installation. Damage
or improper valve timing will re-
sult.
d. Install the clips, camshaft caps "4"
and bolts (camshaft cap) "5".
Bolt (camshaft cap):
10 Nm (1.0 m•kg, 7.2
ft•lb)
• Before installing the clips, cover the
cylinder head with a clean rag to
prevent the clips from into the cylin-
der head cavity.
• Tighten the bolts to the specified
torque in two or three steps in the
proper tightening sequence as
shown.
The bolts (camshaft cap) must be
tightened evenly, or damage to the
cylinder head, camshaft caps, and
camshaft will result.
2. Install:
• Timing chain tensioner
Installation steps:
a. While pressing the tensioner rod
lightly with fingers, use a thin
screwdriver and wind the tension-
er rod up fully clockwise.
b. With the rod fully wound and the
chain tensioner UP mark "a" fac-
ing upward, install the gasket "1",
the timing chain tensioner "2", and
the gasket "3", and tighten the bolt
"4" to the specified torque.
Bolt (timing chain ten-
sioner):
10 Nm (1.0 m•kg, 7.2
ft•lb)
c. Release the screwdriver, check
the tensioner rod to come out and
tighten the gasket "5" and the cap
bolt "6" to the specified torque.
Tensioner cap bolt:
7 Nm (0.7 m•kg, 5.1
ft•lb)
4-12
CAMSHAFTS
3. Turn:
• Crankshaft
Counterclockwise several turns.
4. Check:
• Alignment mark
Align with the crankcase align
mark.
• Camshaft match marks
Align with the cylinder head sur-
face.
Out of alignment → Adjust.