Yamaha YZ450FX 2019 Owner's Service Manual page 105

b. Align the top dead center (TDC) mark "a" on
the rotor with the alignment mark "b" on the
crankcase cover.
TIP
Check that the alignment mark "c" on the cam-
shaft sprocket and the alignment mark "d" on the
intake camshaft sprocket are aligned with the
edge of the cylinder head.
d
c. Measure the valve clearance "e" using a
thickness gauge "1".
Thickness gauge
90890-03268
Feeler gauge set
YU-26900-9
TIP
Record the measured reading if the clearance is
incorrect.
e
b
a
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
5. Adjust:
• Valve clearance
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Remove the camshaft (intake and exhaust).
Refer to "CAMSHAFT" on page 5-11.
b. Remove the valve lifter "2" and the adjusting
pad "3" with a valve lapper "1".
TIP
• Place a cloth in the timing chain space to pre-
c
vent adjusting pads from falling into the crank-
case.
• Identity each valve lifter and adjusting pad po-
sition very carefully so that they can be rein-
stalled in their original place.
Valve lapper (ø14)
90890-04101
Valve lapping tool (14mm)
YM-A8998
e
3-17
ENGINE
1
2
1
3
2
3