Yamaha F150B Service Manual - page 251
7-38
Cylinder head
0
1
2
3
4
5
6
7
8
9
10
A
Removing the cylinder head
1.
Remove the valve lifters from the cylinder
head.
2.
Remove the cylinder head bolts in the
sequence numbers (a,
b, · · ·).
NOTICE: Do not scratch or damage
the mating surfaces of the cylinder
head and cylinder block.
3.
Remove the intake and exhaust valves.
TIP:
Make sure to keep the valves, springs, and
other parts in the order as they were
removed.
Checking the valve lifter
1.
Check the valve lifters. Replace if dam-
aged, scratched, or worn.
2.
Measure the valve lifter outside diameter.
Replace if out of specification.
Checking the cylinder head
1.
Eliminate carbon deposits from the com-
bustion chambers and check for deterio-
ration.
2.
Check the cylinder head warpage using a
straightedge a and thickness gauge b
in the directions shown. Replace the
cylinder head assembly if above
specification.
Valve spring compressor a:
90890-04019
Valve spring compressor attachment b:
90890-06320
(T55)
a b
c
d
e
f
g
h
i
j
k
l
m
n
o
p
q
r
s
t
a
b
Valve lifter outside diameter a:
32.982–32.997 mm (1.2985–1.2991 in)
a
b
a