Yamaha F150B, Service Manual

Page: 120 / 458

4-15
TRBL
SHTG
Troubleshooting
Symptom
1: High engi
ne idle
speed (b
elo
w
1
200
r/min
).
Lo
w
co
m
p
re
s
s
io
n p
res-
sure
Da
mag
ed pist
on
—
C
hec
k t
he comp
re
ssion
p
re
s
su
re
.
Disa
s
se
mb
le
and
ch
ec
k t
h
e
p
o
w
e
r
uni
t.
7-
1
7-
36
7-
45
Scr
a
tche
d cylin
de
r
—
Da
mag
ed v
a
lv
e
—
V
a
lv
e
st
uc
k
to
v
a
lv
e
guid
e
—
Sym
p
to
m
2
C
au
se
1
C
a
u
s
e
2
C
he
c
k
in
g
ste
p
Ref
e
r to
pa
ge
—
Air
leaka
ge (t
h
rot
tl
e v
a
lv
e–
cylin
der
hea
d)
—
Chec
k t
h
e
O-
ri
ngs a
nd g
a
sk
et
s of
t
he
int
a
k
e
silence
r and
int
a
k
e
ma
nif
o
ld
.
6-
16
6-
27
Thr
o
tt
le
l
ink
m
a
lf
unct
ion
—
C
hec
k t
he t
h
ro
tt
le
lin
k
fo
r cla
c
k or
w
o
rn
.
6
-1
8
T
h
ro
tt
le lin
k
an
d
th
ro
ttle
c
a
b
le ar
e no
t
inst
alled correc
tly
—
Adju
st
th
e t
h
ro
tt
le
lin
k an
d t
h
ro
tt
le
cab
le
.
10-
16
Sym
p
to
m
2
C
au
se
1
C
a
u
s
e
2
C
he
c
k
in
g
ste
p
Ref
e
r to
pa
ge