Yamaha F150B, Service Manual

Page: 216 / 458

7-3
Power unit
POWR
6. Measure each valve clearance
e
and
f
according to step 7–step 9.
TIP:
Note the measurement data.
7. Measure the intake valve clearance for
cylinders #1 and #2, and exhaust valve
clearance for cylinders #1 and #3. Adjust
if out of specification.
8. Turn the flywheel magnet 360° clockwise.
9. Measure the intake valve clearance for
cylinders #3 and #4, and exhaust valve
clearance for cylinders #2 and #4. Adjust
if out of specification.
Adjusting the valve clearance
Adjust the valve clearances when the engine
is cold.
• Do not turn the flywheel magnet coun-
terclockwise, otherwise the water pump
impeller may be damaged.
• Do not turn the flywheel magnet or the
driven sprockets when the timing belt is
not installed. Otherwise the pistons and
valves, or intake and exhaust valves will
collide with each other and be damaged.
1. Align the “TDC” mark on the flywheel
magnet with the pointer, and check that
the “I” marks on the driven sprockets are
aligned. See “Checking the valve clear-
ance” (7-2) step 1–step 5.
2. Remove the flywheel magnet and
Woodruff key. See “Removing the
flywheel magnet” (7-6).
3. Disconnect the stator assembly coupler
a
and pulser coil coupler
b
, and then
remove the blowby hose
a
and stator
assembly (lighting coil)
b
.
Valve clearance:
Intake
e
:
0.20
±
0.03 mm (0.008
±
0.001 in)
Exhaust
f
:
0.34
±
0.03 mm (0.013
±
0.001 in)
a
b
c d
e f
EX IN
#1
#2
#3
#4