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nta cting
fuel bowl
g
sc
r e w
g screw.
tall id le
ertight e n
g
adjust -
shutter is
us
sup ply
mixture
'gh speed
,
main
fuel
ught into
fuel which
the idle
fuel
the
'N GINES
D
ry paragraphs
.
Principles
of adjus t
lent
are
s
imilar
for
all mod
els
but
t
he
recedure differs
on
ea
r ly
units
wh
ich
lave
not
been
upd
at ed.
Th
e
CD
units
~e
show n in F
ig.
5.
On
ea
r ly
unrnodi
ned
units , check
plug (C)
was
t
o
th
e
~gh
t
of
re turn fittin g
(R ), or
bleed
plu
g
lretur
n fittin
g was not install ed . Most
early
car buretors
have been modifi ed
o
y
insta lling
late
fu
el
pump
body,
in
Ih
ich case
carburetor
will
be
adj us te d
~
a
lat
e
un
it.
FUEL
LEVEL.
F
ue l
lev el
mu
s t be
.ecked with eng ine ru
nning.
In
st all
.
u
ght
t
ube
(T-Fig.
5) as
show n,
t
he n
ilart and run
e
ng ine at
a
pprox ima te ly
1
500
rpm
. Fuel lev el
should
r
ise
.
in
jlast ic
sigh
t t
u be t
o
low
er g
as ke t
illJ'face
of
upper fuel pump cove
r
(4)
.
n
models
with
ea
r ly
fuel
pump
body
sake
sure sight
t
ube
is inst alled
in
IG HT
port ope ning and
ad
j ust
fuel
level to upper
gask et
sur face of
upper
rover.
If
fu
el le vel is
in
corr e ct , loos en
Ocknut (L) and turn adj usting stud (A)
i N
to
RAISE fuel le vel
or
OUT
t
o
LOWER fu
el le vel.
NOTE:
Some early models
rna
,o ck
screw
(19-Fig. 12
)
c
u re
idjusling stud
(A-
Fig.
!;
I
I
s
tead of
bcknut
(l).
\,
,
;
.
1
,
cor r
ectl y.
adj usted
at
J.
raise
re
ar of
machine a
nd
...
engine at 3000
r
pm;
fuel
level
~o u l
d
not cha nge. If
fuel le
vel
varies
cor rect adj ust me nt
ca
nno
t
be
ob-
fig
.
8-Fuel pump d
iaphragm
(2)
installed
o
n carburetor
body.
Install large
"0
"
ring
(3)
Ind small
"0"
ring
on fuel ports (X) of fuel
pump upper cover (4).
tain ed , overhaul
ca r buretor
as outlined
in appro pr iate
following pa
r agra phs
.
MIXTURE
ADJ
USTMENT. Normal
int itial
se
ttings are 1
1
/4-tu rns open for
idle mixture
adj ustme nt scre w
(I-Fig.
5)
a
nd one-t urn
open
for
high speed
mix
ture sc
rew
(H ).
F
inal
adj us t
me
nts
mu
st be made for best performan ce
wit h
e
ng ine at operating
temperature
a
nd
fuel level properly
adj us t ed .
High
sp
e e d
m
ix bure
mu
st be
r
e ch e ck ed
wh
en ever idle mixture has been
r
ead
ju
st ed
.
OVERHAUL
To
dis
assemble th
e Keih in diaphragm
ca
r b u reto r, r
em o v e
th
e
s
ix
Phill
ip s
head t
hro ug h-bolts
a
nd carefully separ
a
te t
he uni
ts.
Ch
eck t
hro ttle sha ft
a
nd
bor es for wear
and
t
hro ttle
s
hut te r
for
damage
a
nd r
en ew t
he car bure tor if
damage is
found
.
Choke compo ne nts
are available and
may
he
re
newed ,
howe ver, new
scre
ws
m
ust
be used a
nd
s
ta ked
or i
ns
t
all e
d
wit
h
"Locti t e ."
Rernovr
l"g
speed
adj us ti ng
sc
re w
(11
I
l )
and idle ad
ju sting
scre w (I ),
,1
,1
:
exa mine tapered e
nds
for dama ge.
Renew scre ws if
tapered
ends
are
visi bly
ri
nge d or if
ot
herwise dam
aged .
Ren ew
car bure to r if adj us ti ng
sc
re w
seats are dam aged
.
Rem ove
idle
by pass
cover
(I-Fig. 6)
a
nd
its
gasket
a
nd examine
idle we
ll
a
nd
por
t dr
illings for
dirt or
gum.
Soa
k
in so
lvent
an
d
blow ou t with com
pr
essed
air
if dep osits
are
found . Do
not
use a
drill or wir
e probe
in
a
n
Fig . 9-Fuel
pump upper cover
(4)
installed
on carburetor
body.
Position check valve (5)
over upper cover
with
the three
cente;
flaps
centered over
i
n l e t ports (lP) and fuel
passages (X) open
.
'
.
Carburetor Service
attempt
to
clea n
ports. Reinstall idle
bypass
cover
(I)
as show n in
Fig.
7,
tig hte ning
retain ing
scre ws
sec
ure ly.
Chec k
mai n nozzle
expansio n plu
g
(M)
to
be s
ure
it is
tight
a
nd correctly
install ed
.
Do
not
a
t te mpt t
o re
move
expansio n plu
g
or ma
in nozzle.
Wh
en rea ssembling
carburetor, fuel
ma
in
and id le
s
upply
passage
(X
)
mu
st
re mai n
ope n. In
stall gasket
(1)
a
nd
pump
diaph ragm
(2-F ig.
8)
making
s
u re
hol e s
for fu
el passage
s
a
lig n
.
Install t
he
large
"0"
r
ing
(3)
an
d
t
he
tw
o sma ll
"
0"
rings
(in fue l ports "
X " )
in
fuel
pump
upper
cover
(4)
and
p
osition cove
r ov
er t
he d
ow el s
in
throttle body .
Install
chec k
valv e
(5-
F
ig.
9)
making
sure th
e
th
ree middl e fla
ps are
ce
n
t
ered
over
inlet
ports
(IP) in upp
er
cover
(-1 )
an
d
t
hat fuel
ports
(Xl
a
lig
n.
T
he
six check
flap s MUS
T
be
in good
conditio n.
If inlet
need le
val
ve seat is to be
r
enewed , rem ove Phillips head scre
w
(S-Fig.
10)
a
nd r
etain er
(R ). In
vert
p
ump
body a
nd
rem ove va
lve
le ver,
spr ing
a
nd
needl e va
lve;
t
he n
usin g a
Fig
.
10-Top view of fuel pump tower
body
(6)
showing
outlet port» (OP) and top
side
of inlet valve seat (V). Seat
i
s
secured
by
tetsinet
(R)
and screw
(S).
Fuel
passage
potts.
ale at
(X).
Fig
.
ll-Inlet valve lever button
(B)
should
be flush with ttoor on bottom side of val
ve
body
(6).
Inlet valve seat is at (V) and in let
needle at
(N).
121
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