Operation Manual

PERIODIC MAINTENANCE
3-6
TIP
• TDC on the compression stroke can be
found when the cylinder #1 camshaft lobes
are turned away from each other.
• In order to be sure that the piston is at TDC,
the alignment mark “c” on the intake cam-
shaft sprocket and the alignment mark “d” on
the exhaust camshaft sprocket must align
with the cylinder head mating surface as
shown in the illustration.
c. Measure the valve clearance with a thick-
ness gauge “1”.
TIP
• If the valve clearance is incorrect, record the
measured reading.
• Measure the valve clearance in the following
sequence.
d. To measure the valve clearances of the
other cylinders, starting with cylinder #1 at
TDC, turn the crankshaft clockwise as
specified in the following table.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
9. Remove:
• Camshafts
TIP
• Refer to “CAMSHAFTS” on page 5-8.
• When removing the timing chain and cam-
shafts, fasten the timing chain with a wire to
retrieve it if it falls into the crankcase.
10. Adjust:
• Valve clearance
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Remove the valve lifter “1” and the valve
pad “2” with a valve lapper “3”.
Valve clearance measuring sequence
Cylinder #1 → #2
A. Front
A. Degrees that the crankshaft is turned
clockwise
B. Cylinder
C. Combustion cycle
Cylinder #2 360°
Valve lapper
90890-04101
Valve lapping tool
YM-A8998
#2 #1
A
A
B
#1
#2
C
C
0˚ 360˚ 720˚