Yamaha WR450FB 2012 Owner's Service Manual page 95

7. Install:
•Spark plug
~
,.,. Spark plug
~~
13 Nm (1.3 m·kgf, 9.4 ft-lbf)
TIP _ _ _ _ _ _ _ _ _ _ _ _ _ _
Before installing the spark plug, clean the spark
plug and gasket surface.
8. Install:
• Spark plug cap
•Fuel tank
Refer to "FUEL TANK" on page 8-1.
• Air scoop (left/right)
• Side cover (left/right)
•Seat
Refer to "GENERAL CHASSIS" on page 5-
1.
EAS10X3081
ADJUSTING THE VALVE CLEARANCE
The following procedure applies to all of the
valves.
TIP _ _ _ _ _ _ _ _ _ _ _ _ _ _
• Valve clearance adjustment should be made
on a cold engine, at room temperature.
• When the valve clearance is to be measured
or adjusted, the piston must be at top dead
center (TDC) on the compression stroke.
1. Remove:
•Seat
•Fuel tank
Refer to "FUEL TANK" on page 8-1.
2. Remove:
•Spark plug
• Cylinder head cover
. Refer to "CAMSHAFT" on page 6-7.
3. Remove:
•Timing mark accessing screw "1"
• Crankshaft end cover "2"
• 0-ring
3-7
PERIODIC MAINTENANCE
4. Measure:
•Valve clearance
Out of specification
~
Adjust.
~
Valve clearance (cold)
v
~
Intake
0.10-0.15 mm (0.0039-0.0059 in)
Exhaust
0.20-0.25 mm (0.0079-0.0098 in)
yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy
a. Turn the crankshaft counterclockwise.
b. Align TDC mark "a" of the generator rotor
with mark "b" of the generator rotor cover.
r
~~
s:
y~
TIP _ _ _ _ _ _ _ _ _ _ _ _ _ _
In order to be sure that the piston is at Top
Dead Center, the punch mark "c" on the ex-
haust camshaft and the punch·mark "d" on the
intake camshaft must align with the cylinder
head surface, as shown in the illustration.
'
c. Measure the valve clearance with a thick-
ness gauge "1 ".
~
Thickness gauge
~- 90890-03180
Feeler gauge set
VU-26900-9