The Washington herald., 1917-02-25
CROSS EXAMINING AUTO
ON WHY IT WON'T RUN.
Finding Out What's Wrong Is Like
= Hunting for Criminal

: Huntins for Criminal
Finding out the trouble with an auto
aobile when It won't run is. aecording
. experts, Ike running down Q crime.
It b . process Of cool and losical elm
ination Tia motoftst, unless Ne pe An
expart himself, reading sounds and signs
wtfh swift and unfaiiing accuracy a. to
their cause, should first clear his mind
Of an prsjudices and passion. Every
rreconception should be magnanfmousiy
dismissed from his thoughts, no matter
how great his haste, how inciement the
weather., before, seeking the truth and
nothing but the truth. he begins to Cross
question the auto by trying one part
after the other
Nor a. the process Of elimination one
which the motorist may follow accord
ing to his own notion. As IN the courts
of Justice and IN the laboratory OF the
chemist and OF the mechanical engineer.
thsrs IN a rfxht order in seeking out
the true cause What this order II for
the stalled automobile. II. c. Brokaw.
principal OF the West Side Young Mems
Christian Association Automobile School.
New York, describes IN the following:
II the engine stops on the road and
pressing the starter pedal fails to start
II, the hrst thing to do is to get the
crank out Of the too kit and crank over
the engine II with the gears IN neu-
raj. the engine cranks over hard. II In
dicatss . lack OF luoricating oil or q
lack Of water, which has allowed the
engine to reach the Temperature where
the lubricant failed to perform its work.
II the engine turns over fairly easy IL is
not necessary to look for oil or water
trouble
Test for Compression.
the driver il not experienced and Ii un-
able to tell simply by the resistance to
the starting crank II each cylinder has
compression. he should open all petcocks
except on one cylinder and turn the crank
two revolutions, noting II there ID . re-
sistanos for one-Quarter Of Q revolution
in the two revolutions Compression oc-
ours only on one stroke Of the piston IN
the four-stroks cycle. Each cylinder should
be tested In a similar manner, opening all
petcocks except on the cylinder being
tested; see II the compression IL prac-
tically equal in all cylinders.
If enc cylinder has very weak or no
compression. the trouble will Be found
usually In the exhaust valve First sx-
anime the push rod to zee II there II
clearance between II and the valve when
the valve Is supposed to be closed; u
there Is, the valve must be lifted out
ION. Sometimes Q piece Of carbon viii
lodge on the valve seat and. due to the
hammering of the valve. viii become
fastened to valve or seat For temporary
repair generally II can be scraped on
with a knife and the valve be ground In
upon reaching the garage.
If the trouble Is not IN the exhaust
valve. il might be in the inlet valve. In
sIme type Of engines the valve head may
~. Na,-ls -
when the piston comes up punch Q hole
in the piston head. A petcock may be
loose so that 1t viii jar open sufficiently
to affect the compression and 30 cause
the cylinder to miss fire- These troubles
usually are confined to one cylinder and
rot to the whole engine.
The gasoline is the next to be inspect
Cd. Is there gasoline in the bowl Of the
Carbureter? This may be determined BY
inspection. opening drain cock or tick
i'ng'-floCding. II not. examine gasoline
tank and see II there is a supply; then
rre IL 1he shutOff valve in the line leading
to the cdrbureter is open: II so, drain the
howl Of the carbureter to get rid OF pos
$i1Ie water and dirt. To check the pos
; ble cIogginS of gasoline pipe or carbu-
r"tor screen, notice if the bowl fllls up
aSain in. a reasonable time.
DO Not Adjust Carbureter.
DO not adjust the carbureter. II the
engine has been running it Is practically
certain that the carbureter has not be-
come out of adjustment Inspect the in
take pipe, or manifold, to see II It has
been loosened by vibration. II the en-
Gine still refuses to run, put about a
tablespoonful of gasoline in each cylinder
and crank over the engine. II this runs
the engine for a few revolutions 1t in
dictates that the trouble Is in the gasoline
system and leaves but the spray nozzle,
which may have dirt lodged In it, or the
auxiliary air valve, which may be stuck,
rs remaining causes.
Next inspect the ignition system. The
fIrst thing to do is to loosen one OF the
wires from spark plug and lay or hold
il so the bare end will be one-eighth OF an
inch from the base of the plug and have
some one crank the engine by hand or
with the starter. If spark does not oc-
cur. go first to the interrupter points and
short circuit the fixed point with q screw
driver or other metal tool and see IL
there is spark. Examine the points for
DIRT and see II they come together and
open properly. Then examine the condi-
tion OF the battery. testing It. Examine
the connections on the battery, which
sometimes jar loose; examine the wires
leading to the interrupter switch:
see II they are loose. or broken, or short
c'rcuited. This need not be done II the
spark shows at the interrupter.
Examine the distributor for moisture
or dirt and see IL the wires have become
loose; II magnetic only Is used, It Is a
simple matter to see IL the interrupter
points are making and breaking nrop-
erly and II the distributor is clean and
dry. II these appear to be all right the
trouble Is doubtless in the armature wind
ing or the condenser and cannot ba rs-
paired upon the road"