The Kendrick gazette. [volume] (Kendrick, Idaho) 1892-1968, 1919-06-13

portanee o Knowing a Gasoline Engine.

prepared by the United States Depart
ment Of Agriculture.)
With all engines using spark plugs
It is comparatively easy to ascertain
whether the ignition system Is work.
ing properly. Simply remove plug
and ascertain that the porcelain OF
other insulating material on the inside
of the plug is not coated with carbon
and that the points are properly
spaced. One thirty-second of an inch
is about the right space for most sys
TENS where a dry battery is used. This
is about equal to the thickness Of a
worn dime. A wider gap will often
make starting difficult. especially when
the spark Is rather weak or where a
high tension magnetic Is used. In the
latter case the best results will often
be obtained when the gap is not more
than one-f0rtieth or even one-fiftieth
Of an inch. Then re-attach the wire
and lay the plug so that the metal
base touches the engine casting, while
the end Of the wire and the metal
tip of the plug are at least half an
inch from any metal part connected
with the engine and in such a posi-
ton that the points are visible while
cranking the engine. Then turn the
engine over a few times Cat least as
many times as there are cylinders)
and note whether spark jumps across
the space between the points. It is
not sufficient, however, merely to as
certain if there is spark--it must
be hot enough to fire the compressed
charge in the cylinder. It is, of course,
difficult to tell by merely looking at
it whether the spark is hot enough
or not, but If it is heavy blue, or a
bluishwhite, or 'tfat" yellow one
looking like a small flame, it is prob
ably all right. If very thin and green
ish or showing red, the chances are
it is too weak to fire the charge. One
may familiarize himself with the as
pect Of good spark as follows:
Finding a Good Spark.
While the motor is in satisfactory
running condition loosen the nut on
the top of the plug while the engine is
stopped so it will be easy to remove
the wire from the plug after the en-
CINE is started. Then start the en-
CINE and, by taking hold of the wire
where it is covered with insulation,
move the end of the wire very slowly
away from the center of the plug and
watch the spark jump, closely observ-
ing its color and thickness.
1t is also well to note the distance
the spark will jump, yet not advisable
to force it to jump too great a gap
nor should the end of the wire be al.
lowed to rest in position where the
spark cannot jump to the plug or the
engine while the engine is running, as
this tends to break down the insula.
ton Of the coil. In the case of high.
tension magnetos there is no danger
in this respect, as they are fitted with
a safety spark gap which the spark
will jump, if for any reason the circuit
is broken elsewhere.
knowledge of just how much of 9
spark one should obtain with eacf
kind of ignition system is frequently
of great value in locating trouble, ant
| everyone who operates gas engine
should make the above-described test.
while the engine is in good order. L
one is not sufficiently familiar will
the looks Of u good spark to tell b!
mere observation whether it Is no
enough, a rough test may be mad,
as follows: Place a thin piece O.
dry cardboard, such as an ordinary Wis
iting card, or three or four thicknesse
of dry newspaper, between the point
of the plug while 1t is lying on tn
engine in the position first mentioned
then crank the engine. A good sparl
will jump through these, leaving
tiny hole. A spark which will not d.
this is too weak to jump the spar
gap In the cylinder under compress
sion.
II the engine is equipped with
make-and-break ignition system. Il
which an igniter block is used instea
Of spark plug, it can be ascertaine
easily whether the entire system. wit
the exception Of the igniter block, 1
In good shape by disconnecting TIL
wire from the igniter block and SNAP
ping 1t across the corner of the er
CINE casting or the end of the othe
wire leading from the coil. But eve
though this gives good spark
does not necessarily mean that tn
spark is given in the cylinder whe
the engine Is turned over. 1t ma
be that the points of the electrode
inside the cylinder do not touch eac
other when they should or are nc
making a good contact. because cal
bon, oil, dirt, ETC., have accumulate
between these points. Therefore,
good spark occurs when the wire
snapped across part of the engin,
crank the engine until the movabl
electrode is released and allowed I
fly back.
Contact Not Being Made.
If one Is not sure just when TIL
points Of the electr0de should be tOucl
ing, the engine may be cranked yer
slowly for two full revolutions Will
the end of the wire is repeated
snaDDed across rs connection IN fl