Filter
Top Products
20
Engine
Tractors,
Lawn
and
Garden
-
110
and
112
25-2
General
Information
-
Tecumseh
SM-
2059-
(Apr-
6 7)
ENGINE
ANALYSIS
PRELIMINARY
ENGINE
CHECKS
A
complete
guide
for
diagnosing
engine
mal-
functions
appears
on
page
25-4.
However,
the
majority
of
engine
trouble
reports
are
of
a
minor
non-chronic
nature
and
are
usually
due
to
elec-
trical
or
fuel
system
difficulties.
First
make
the
c
hecks
listed
below
to
isolate
the
majority
of
engine
problems.
Fig
.
2-Checking
Spork
ot
P/uq
Check
spark,
Figure
2,
whenever
engine
will
not
start.
If
engine
will
not
crank,
follow
diag-
nosing
procedure
on
page
25-4.
Remove
ignition
cable
from
spark
plug
and
in-
stall
adaptor
or
ordinary
paper
clip.
Hold
ap-
proximately
1/4
inch
away
from
grounded
engine
shrouding
while
cranking
the
engine.
If
there
1s
no
spark
at
the
adaptor
or
a
weak
spark,
the
trouble
is
in
the
electrical
system.
If
the
battery
and
spark
plug
are
good
and
all
elec-
trical
connections
are
tight,
the
trouble
most
likely
is
in
the
breaker
points
and
condenser.
Clean
or
replace
points
and
adjust
gap.
If
break-
er
points
are
burned,
replace
the
condenser
also.
If
there
is
good
spark
between
the
adaptor
and
the
grounded
surface,
the
problem
is
in
the
fuel-
air
system.
If
gas
tank
is
full,
check
shut-off
valve
on
sediment
bowl
and
gas
lines
to
carbu-
retor
to
be
certain
gas
is
getting
to
carburetor.
Open
carburetor
valves
as
instructed
in
Section
30,
Group
10
.
Connect
high
tension
wire
tospark
plug
and
crank
engine.
Choke
as
necessary.
If
engine
still
does
not
start,
refer
to
"Diagnosing
Malfunctions"
on
page
25-4
to
check
for
internal
difficulties.
If
the
engine
still
does
not
start,
or
starts
but
does
not
run
properly,
make
the
compression
test
on
this
page
and
the
vacuum
test
On
page
25-3.
PRELIMINARY
ENGINE
TESTS
The
following
preliminary
e n
gine
tests
are
recommended
to
detect
and
isol
a
te
possible
mal-
functions
before
proceeding
with
further
dia
g-
nosis.
These
tests
are
especially
important
wh
e n
engine
is
burning
oil,
loosing
power
or
runni
ng
erratically
and
when
carburetion
and
ignition
ad-
justments
do
not
correct
the
condition.
COMPRESSION
TEST
The
HHIOO
Engines
are
equipped
with
an
in-
stamatic
EZEE-start
compression
release
cam-
shaft.
They
will
be
referred
to
as
"EZEE-start"
in
Section
20
of
this
service
manual.
The
EZEE-
start
feature
releases
compression
pressure
during
lower
cranking
speeds.
It
is
important
to
crank
the
engine
at
1000
rpm,
or
more
to
obtain
an
accurate
test.
The
EZEE-start
mechanism
is
disengaged
when
the
tachometer
reads
approxi-
mately
650
rpm.
When
the
engine
is
operable
in
the
tractor,
check
compression
as
follows.
Fig.
3-
Testing
Engine
Compression
Depress
clutch-brake
pedal
and
set
parking
brake.
Be
sure
oil
in
crankcase
is
at
proper
lev
el
and
battery
is
properly
Charged.
NOTE:
Be
sure
tractor
drives
are
all
disen-
gaged.
Run
engine
until
warm.,
then
s top
the
en-
gine.
Remove
spark
plug.
Also
remove
air
filter
for
most
accurate
test.
Litho
in
U.S.A.