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invisible gas, which
if
breathed
into
the
lungs would
cause serious illness and possible
death.
Never
make adjustments on
any
kind of machinery
while
it
is connected to the
engine
without
first re-
moving
the
ignition cable
from
the
spark
plug. Turn-
ing over the machinery by hand during adjusting
or
cleaning might start the
engine
and the machinery
with
it,
causing serious injury
to the
operator.
Always
keep
all
ports
of
the
engine
clean. This
wi II prolong
engine
I ife,
one/
give more
satis-
Factory
operation,
Every
4
to
8
hours,
depending
on dust
conditions,
check air cleaner and change
oil
if dirty.
See
Page
7.
Every
8 hours
check
crankcase oil
level.
Keep filled
to
level
of
oil
filler
hole.
See
Page
7.
fv,ery
SO hours
drain
crankcase
and refill with fresh
oil. See Page 7.
TROUBLE
CAUSES AND
REMEDIES
Three prime
requisites
are essential to starting and
maintaining satisfactory
operation
of
gasoline en-
gines.
They are:
1.
A proper Fuel
mixture
in the cyUnder.
2.
Gooc/
compression
in the
cylinder.
3.
Gooc/ spark, properly
timed, to
ignite
the
mixture.
If
all three of
these conditions
do not exist
the
en-
gine cannot
be started. There are other factors which
will
contribute
to hard
sta
rting;
such as, too
heavy a
load for the
engine to
turn over at
a
low starting
speed,
a long exhaust pipe with high back pressure,
etc. These
conditions may
affect the
starting,
but do
not necessarily mean that the engine is improperly
adjusted.
As
a guide
to
locating any
difficulties
which might
arise, the
following causes
~1re
listed under three
headings:
Fuel
Mixture, Compression,
one/
Ign
ition.
In
each
case
the
causes of
t rouble are given in the
order
in which they are most apt
to occur.
In
many
cases
the remedy is apparent, and in such cases no
further remedies
are
suggested.
STARTING DIFFICULTIES
FUEL
MIXTURE
No
fuel in tank or fuel
shut-off
valve
closed.
Carburetor not choked
sufficiently,
especially if en-
gine
is
cold.
See 'Choke', Page 8.
Water,
dirt,
or
gum in gasoline interfering
with
free
flow
of
fuel to
carburetor.
Poor grade
or
stale
gasoline
that will not
vaporize
sufficiently, to form the
proper
fuel
mixture.
Needle
valve
on
carburetor
insufficiently
opened.
Carburetor flooded
,
caused
by too much choking es-
13
pecially
if engine is hot.
See
'Choke',
Page
8.
Dirt
or
gum
will
hold float
needle
valve in carburetor
open.
This
condition
would
be indicated if fuel con-
tinues
to
drip from
carburetor while
engine
is
idle.
Often tapping.
the
fleet
chambe
r
of
the
carburetor
lightly with
the
wood
handle
of a screw
driver or
sim-
ilar
instrument will
remedy
this trouble.
Do not strike
with any
metal tools,
it may cause
damage.
Also if
the mixture
in
the
cyl inder,
due
to
flooding,
is not
too
rich, starting may be accomplished
by continued
cranking
with
the
carburetor
choke open.
If due to flooding, too
much
fuel should
have entered
the
cylinder
in
attempting
to
start the engine,
the
mixture
will most likely
be
too
rich
to burn.
In
that
case
the spark plug should
be
removed from the
cyl-
inder and the engine then turned
over
several times
with the starting
rope,
so the rich mixture wi 11
be
blown out through the spark plug hole. The
choke on
the
carburetor
should of course be
left
open during
this
procedure.
The plug should
then
be
replaced
and
starting tried again.
To test
for
clogged fuel line, loosen fuel hne nut at
carburetor slightly.
If line
is
open,
fuel
should
drip
out
at loosened nut.
COMPRESSION
If
the engine has proper compression,
considerably
more
resistance will
be encountered in the pull
on
the s
tarting rope,
on one stroke of
the
piston as com-
pared wiU1
the
other
three
strokes.
If
this resistance
is
not encountered,
compression
is
faulty.
Following
are some reasons
for poor compression:-
Cylinder dry
due to
engine
having been
out
of
use for
some
~me.
See 'Restoring
Compression', Page
11.
Loose
spark
plug
or
broken spark plug. In this case
a
hissing
noise will be heard in
c
ranking
engine, due
to
escaping
gas mixture on compression
stroke.
Damaged cylinder head gasket or loose cylinder head.
This
will
likewise cause
hissing
noise on compress-
ion
stroke.
Valve stuck open due to carbon or gum on
valve
stem.
Remove
tapper
inspection
plate and note if
valves
a
re
moving
up
and down as engine is turned
over
by
hand.
A stuck valve
will
not
follow down. To
clean
valve stems, see 'Valves', Page
18.
Valve
tappets
adjusted
with insufficient clearance
under
valve stems
.
See
'Valve Tappet
Adjustmer~t',
Page
19.
Pistons rings stuck in piston due to carbon accumu-
lation.
If rings
are stuck very tight, this will neces-
sitate removing piston and
connecting
rod assembly
and cleaning
parts.
See
'Piston and
Connecting
Rod'
Page
16.
Scored
cylinder.
This will require
reboring
of tht:
cylinder
and fitting with new piston
and rings. If
scored
too
severely, an enti re
new
cylinder
and crank
case
may
be
necessary.
Ml·218
..
4
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