Filter
Top Products
20
Engine
Tractors,
Lawn
a
ncl
Ga
rden
-
110
;:md
112
10-2
CylinUl'l"
Head
and
Valves
-
Kohler
SM-
2059-
(Apr-57)
VAL
VE
ANAL
YSI
S
Fig.
2 -
Lcad
Dopo<
" ,
On
Leak
y
I,,'ake
Valve
Lead
deposits
on
the
intake
valve
consist
mo
s
tly
of
lead
and
some
metal
w
hich
Comes
from
the
lubricatin
g
oil.
It
is
caus
ed
by
a
small
amount
of leakag·e
uf
exhaust
[.';ases
back
into
th
e
intake
port
area.
This
indi
ca
tes
that
th
e
valve
is
not
seating-
prop
e
rly.
Grind
the
valv
e
and
H'face
the
seat
to
corr
ect
this
conditi
on.
NOT
I';: IJe
sure
10
coyrec(
caZre-to
-tappel
cleaYUlICe
olley
griJld-
i
nK
l:all.'es.
Sec
/JaKe
10-8.
\1
""1
Fig.
J-Vo
l
ve
S'em
Corrosion
Valve
stern
corrOSion
is
caused
by
moisture
finding
its
way
into
the
eng
ine.
Moisture
in
th
e
fuel-air
mixture
can
condense
insid
e
the
engine
when
engine
is
stopped
before
it
has
had
a
chanc
e
to
warm
up.
Valve
corrosion
can
also
oc
c
ur
during
stor-
a?;e
when
the
en?;ine
has
not
been
run
for
Some
time.
Foggin(!; or
pouring
oil
in
the
co
mbustion
chamber
before
storing
will
prevent
valve
corro-
s ion.
Curroded
and
pitted
val
ve
s te
nd
to
collect
de-
posits
which
in
turn
c, u
ses
alv
e s
tickin
"·.
Al-
way
s
replac
e
badly
c
or
r oded
or
pitted
valv
!~s
with
new
va
lv
s .
Fi
g.
4-Ex
!'oust
Volve
Running
Too
H
ot
Exhaust
va
lves
are
d
es
ip;n
ed
to
functi
on in
temp
era
tur
es
ex
eed
in
g-
5000°
F .
However,
wt"n
op
era
tin
g
at
this
temp
r
atu
re
for
l
on
g
periods
of
time,
valve
burnin!?:
occurS.
Tell-tale
Si:-;11
8 of
valves
running
t
oo
hot
i:
)
the
dark
discoloration
of
the
valv
e
stem
down
into
the
alca
pro
tected
by
the
valve
guide.
AnotlJPr
indication
is
disfig-
uration
of
the
val
ve
mar
gin
and
valve
face.
Valve
in
se
rts
may
a
ls
o b
egin
to
burn
away
.
The
most
common
ca
use
of
an
ov
(
~
dleated
en-
g
ine
and
valves
is
poor
cooling
due
to
dirt
or
obs
tructions
inside
the
intak
e
shrouding.
TIe-
move
and
cl
ea
n
shroudinf';
and
all
cooling:
fins
on
th
e
engine
if
this
condition
is
noticed.
j
"()7F.·
Ne
v
ey
rim
enl
.,rille u:
ith
sln·ouding
Yerl!ol'ed.
Also
check
for
impr
oper
valve
timing
by
checking;
and
correctin~r,
va
lv
e
clearance.
Worn
valve
guides
or
valve
springs
can
alsu
cause
overheated
valves.
Val
ves
running
hot
can
also
be
caused
by
im-
proper
spark
plu?;
or
overheated
spark
plugs
which
cause
pre-ignition
or
a
lean
fuel
mixture.
Litho
in
U.S
.A.