Evening star., 1924-09-07
HINTS ON ERRAT|C'
ACTION OF ENGINES
Some Slight Trouble Over
looked Cause of Worry at
Service Stations.
BY JIMMY MURPHY.

Many service stations have been
bd,Hed by the actions OF certain en-
Sifes in performing erratically. own
@rS have come 10 me with complaints
about misfiring and loss OF power
nyerheatiug and other troubles. and
state that apparently everything has
been done by the hest mechanics in
rho city, and still there are no salts
factory results. Very often in cases
u this kind some Slight trouble fs
overlook ed. Take the recent example
hat has come to my attention of
ease of misfiring of an Overland road
ster. First. the carbureter was sus-
pected and the mechanic .oYerhauled
L II did no good. Then the mag
1eto was suspected, but found Q. X.
Valves were checked and everything
possible seemed 10 have been at
tended to, but the motor showed lack
Of power and misired on occasions
1t 50 happened that no one took the
trouble TO examine the fuel line care
fully. 1t was discovered that the
oipc (Which runs from Il cowl tank
through d hole in the daSh) was
bad. = twisted and dented at one
point. This could hardly he noticed
without either removing the line or
ceiling every inch of it, because the
INSTRUCTED portion was right at the
opening in the dash. Naturally. the
''arburcter float bowl did not fill fast
enough, and when the engine de-
.uands were heavy. as on a grade.
mIsfiring would result Dirt in the
line or much in the gasoline tank
would give the same results.
Occasional MiSfring Cited.
IN a case showing misliring only at
n'n1"s and not always on Z. grade the
'ntire engine was gone over cX-
ternally. Then the valves were
ground because compression in two
"yllnderS was very poor. The igni-
lion was pronounced O. X. carburete er
n good condition. valves properly
timed, etc. Still the owner had the
same trouble and could find no one
in his small community TO locate the
cause. 1t developed that one piston
had a slight crack in its head and at
he same time was so loose in the
'Ilindnr. due TO the excessive wear.
that the cylinder would only take in
a. proper change at times. It was this
cylinder which was misfring at Ger
tain periods.
The trouble with many who at
tempt to find the cause of trouble is
that they do not go over each system
thoroughly and attend to every pos
sihle part that might cause the
trouble. Fer example. after checking
ignition and carburetior and finding
them .. h, the valves should be
gone over. This ma i>eS the three
important systems but not by any
means the only three causes of lack
of power. rnjsfrin~, hard starting,
oVerheating ard other engine trou-
bles. car two months ago was de-
iVeIed to an owner, and while on
the road the engine sputtered and
stopped. 1t started again, firing lust
enough to turn the engine over. Every
unit was examined and found o. X.
The mechanic at the shop did not
know what to suspect in car only
two months old. and went through
the engine from spark plugs to igni-
tion and finally checked the valves
and found them out Of time. but this
he discovered was caused by the
timing chain having jumped one
of the Sprockets The chain had
stretched too much.
Should First Test Ignition.
The first thing to do in engine
trouble which has no definite symp-
toms is to check the ignition by lay
ing the plugs with cables attached on
top of the cylinders. Crank the en-
gine by hand and note the spark at
the gaps. If good sparks are pro-
duced, then you can proceed to the
next unit-tbe carbureter. II the
sparks are weak or none at all is
produced in one or more of the plugs
start at the plug end and work to-
ward the ignition source. If the
plugs are in good shape, then the in
sulatton should be examined, then the
terminal a the distributor, then the
distributor itself, and so on.
knowing that the ignition system