Yamaha F150B, Service Manual

Page: 121 / 458

4-16
Troubleshooting the power unit
0
1
2
3
4
5
6
7
8
9
10
A
Symptom
1: Limite
d engine
speed
(belo
w
2000
r/mi
n).
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
Buz
z
er
comes on, o
v
er-
h
eat
ale
rt ind
ica
to
r
comes on, co
oling w
a
ter
d
oes no
t discha
rg
e
fr
om
the cooling w
a
ter pilot
ho
le
Clo
gge
d coolin
g w
a
te
r inle
t
—
Chec
k t
he cooli
ng w
a
te
r inle
t.
8-
8
8-
53
W
a
te
r pum
p malf
un
ct
io
n
W
at
er
pum
p impe
ller
ma
l-
fun
c
ti
on
Chec
k t
he imp
e
ller
.
8-
7
Chec
k t
he W
ood
ru
ff
k
e
y.
8-
7
W
a
te
r leakag
e f
rom
w
a
te
r
pu
m
p
h
o
u
s
ing
Chec
k t
he w
a
te
r pu
mp ho
using
.
8-
7
Chec
k t
he inser
t ca
rt
ri
d
g
e
.
8-
7
Chec
k t
he ou
te
r pla
te ca
rt
ri
d
g
e
.
8-
7
Clo
gge
d coolin
g w
a
te
r passag
e
—
Chec
k t
he cooli
ng w
a
te
r pa
ssag
e (p
o
w
er
u
n
it
,
EX gu
id
e
,
a
n
d
up
pe
r ca
se
).
2-
24
Ther
most
at
malf
un
ct
io
n
—
Chec
k t
he t
her
most
at
.
10-
16
Buz
z
er
comes on, oil
pr
es
su
re
a
ler
t in
dica
to
r
comes on
In
su
ff
icien
t en
gine
oil
—
Add
suf
fi
cie
n
t oil.
1
0
-5
En
gin
e
oil pr
essu
re
d
e
cre
a
se
O
il pum
p malf
un
ct
io
n
C
hec
k t
he oil pr
essur
e
.
7
-2
Clogged oil str
a
iner
Chec
k the oil str
a
iner
.
9
-21
Clo
gge
d oil pa
ssag
e
C
hec
k t
he oil pa
ssa
ge (
p
o
w
e
r un
it an
d oil
pu
mp)
.
2-
22
En
gine
oil leaka
g
e
Clo
gge
d oil f
ilte
r
Repla
c
e th
e oil f
ilte
r.
10-
11