Evening star. [volume] (Washington, D.C.) 1854-1972, 1917-08-12
GOOD HOT SPARK
IS LIFE TO MOTOR
Represents Difference Be-
tween Good and Bad Engine,
Says w. H. Stewart, Jr.
HOW TO GET RESULTS

A good, hot spark decides inc uh-
ference between good motor and
poor one" says William II. Stewart, IT.,
president of the Stewart Automobile
School. Many a motor has been con-
demned because of a sluggish action,
weak power, lack of fexibility and
other faults, and the reason laid to
faulty design. whereas the trouble was
due to q weak spark and the owner did
not know 1t.
The reason for this is obvious. II
the spark is not hot enough the ex-
sDlosion loses a great deal of its snap
piness and the power suffers in conse-
sQuence. Other things being equal. the
power depends directly upon the heat
of the spark. The hotter the spark
The stronger the explosion. The other
factors referred to are carburetion.
Subtraction, compression ana cooilng,
these Ave factors being necessary for
the engine to run and develop full
snow 1t must be explained why
hot spark gives a snappy. explosion.
II you wished to burn a large mass
of rubbish quickly YOU wonld set fire
TO 1t In several places at once II you
set the fire at only one spot 1t will
burn in all probability. but 1t will take
longer and 1t might go out. By light
ing the pile in several places the whole
will be consumed in less time. and II
the IRE goes out in one or two places
the other flames will do the work.
Difference in Sparks.
The analogy in the case of the cleo
trio spark and the explosive mixture
n very close. A weak spark infiames
. few particles of gasoline. These few
set fire to q few more and the ex-
plosion is started slowly. In the case
OF hot spark great many more par
ticles are infiamed at the start These
get nre to larger number and so the
name advances with greater rapidity
through the mass, giving the snappy
explosion required.
TT follows that the spark at all times
be the best obtainable. Al there are
many causes of weak spark, 1t will be
well to take them up one at a time.
First comes the battery. 1t may be
weak. the terminals and wires may not
defective spots In the Insulation Of the
wires. Test the battery with a hy-
0rometer every week. 1t should read
LIS to 1.30O, called twelve seventy-dve
and thirteen hundred, the decimal point
being neglected in speaking but not
~ writing the figures. II the battery II
Below this strength you are using the
starter on lights too much or the gem
Terminals should be Thoroughly cleaned
ana set up tightly with q wrench or
D1fers- Then cup grease or yaseIine
should be smeared over them to pre-
terry. which has a tendency to creep In
between the surface and to insulate
them with . layer Of sulphate. The
wires should be examined occasionally
ana any spots which show chafing
mould be covered with friction tape.
Next Place Is Coil.
The next place Is the coil. If the
secondary winding is punctured or the
condenser leaks. the spark will be too
weak for ignition. This may be caused
By . defect of manufacture. but is
Usually caused by a wire dropping or
4Qlug produced Just the same and. hav-
III its regular path interrupted, it must
jump somewhere. As the spark is
strong enough to jump over e quarter
the coil. Once it punctures the Ursula
t1on the spark win not jump the spark
rap. since 1t has q shorter circuit In.
eioe- There Is no remedy for this con-
p make sure that the spark plug wires
'ere properly secured at all times Also
look to the terminals on the coils, as 4
weak spark will certainly follow II
they become loose or dirty
The interrupter must also make Arm
contact or the battery current will not
develop its full strength. The contact
points must be clean. they must omen
the right distance, and the spring must
De strong Clean the points OCCASION
9tly by drawing Q piece of nne emery
cloth through them and make sure that
the points open the distance advised by
the manufacturers.
Watch Distributor.
The distributor next requires atten-
tton- Current may leak through accu-
situations Of dust and oil outside or in
e1det II outside. the spark may be seen
and heard Sometimes 1t may be heard
3umDing inside- Dust should be 70
moved with a soft cloth dipped in gas
oiine Il does not offer a very good
nefh to the current, but once q spark
Jumps through II the dust is scorched.
FORMING carbon, which Is q good con-
0ucfor. Distributor brushes worn
away, or broken. or loose rotor. will
onuse trouble. See that all the dis
trfbuter wires are firmly fastened and
that no worn spots exist in the insu-
lAtion.
Last, but not least, are the spark
plugs- They may give trouble because
oi carbon. leaky core, spark gap out of
adjustment and corroded points
carbonixed plug should be cleaned with
gasoline. using an old toothbrush The
plug must be taken apart for this.
Mnicn gives an opportunity to inspect