Yamaha YZ450FY 2009 Owner's Service Manual page 97

3. Check:
• Steering smooth action
Turn the handlebar lock to lock.
Unsmooth action → Adjust steering ring nut.
4. Adjust:
• Steering ring nut
Steering ring nut adjustment steps:
a. Remove the number plate.
b. Remove the handlebar and upper bracket.
c. Loosen the steering ring nut "1" using the
steering nut wrench "2".
Steering nut wrench:
YU-33975/90890-01403
d. Tighten the steering ring nut "3" using steer-
ing nut wrench "4".
• Apply the lithium soap base grease on the
thread of the steering stem.
• Set the torque wrench to the steering nut
wrench so that they form a right angle.
Steering nut wrench:
YU-33975/90890-01403
Steering ring nut (initial tightening):
38 Nm (3.8 m•kg, 27 ft•lb)
e. Loosen the steering ring nut one turn.
f. Retighten the steering ring nut using the
steering nut wrench.
Avoid over-tightening.
Steering ring nut (final tightening):
7 Nm (0.7 m•kg, 5.1 ft•lb)
g. Check the steering stem by turning it lock to
lock. If there is any binding, remove the
steering stem assembly and inspect the
steering bearings.
h. Install the washer "5", upper bracket "6",
washer "7", steering stem nut "8", handlebar
"9", handlebar upper holder "10" and num-
ber plate "11".
• The handlebar upper holder should be in-
stalled with the punched mark "a" forward.
• Install the handlebar so that the marks "b" are
in place on both sides.
• Install the handlebar so that the projection "c"
of the handlebar upper holder is positioned at
the mark on the handlebar as shown.
• Insert the end of the fuel breather hose "12"
into the hole in the steering stem.
First tighten the bolts on the front side of
the handlebar upper holder, and then tight-
en the bolts on the rear side.
Steering stem nut:
145 Nm (14.5 m•kg, 105 ft•lb)
Handlebar upper holder:
28 Nm (2.8 m•kg, 20 ft•lb)
Pinch bolt (upper bracket):
21 Nm (2.1 m•kg, 15 ft•lb)
Number plate:
7 Nm (0.7 m•kg, 5.1 ft•lb)
3-32
CHASSIS