Evening star., 1923-05-13
CARBURET0R ILLS
NEED REAL CARE
Systematic Search for
Source of Trouble Vital if
Trouble Is to Be Avoided.

In tracing carburetor trouble of
any kind. regardless of it's nature.
time can always be saved by follow
irg a systematic process of elimina-
tion, eliminating the units. which are
found when tested, to be all right.
In locating carburetor troubles these
can be divided into various groups as
outlined in the chart presented here
with. These can all be traced by GER
tain symptoms. Thus. too lean a mix
ture will cause backfiring and stall
the engine when the throttle is open
ed suddenly. Misfiiing. when due to
carburation. is caused by unequal fuel
distribution, while refusal to start
is due to a lack of mixture at the
carburetOr.
The above troubles frequently pre-.
sent themselves in cold weather ana
toned below. as one is always inter
eSted in obtaining the maximum
economy and likely to favor too lean
a mixture. Troubles due to leaks anG
too rich mixture are more apt ~
be caused by natural wear of the
parts comprising the fuel system.
Must Test Engine.
The first step in shooting carburetor
troubles is to test the engine Whlle
running and noting It's general ac-
ton to establish the symptoms. 10
do this testing it is many times
this should be avoided whenever pos
sible. as 1t will eventually lead 10
troubles of greater consequence. sueli
as loose bearings, noisy engine t,t.
careful study of the symptoms
will readily lead one to the genera
nature of the trouble and then permit
systematic search for the cauSt.
Careful attention to detaiis viii MI,
making the test Is eSseh,,aat nau ,oca- a.. =
ton and repair of the trou.ie.
trouble should never be looked Ior
In the carburetion system unless tne
engine is warm ana III soou
condition otherwise "a
iustment can be determined by @ me
jdlfng condition of the engine. TOO 90
lean a low-speed adjustment VIII
cause the engine to idle poorly ana IL
medically. An extremely rich adjust
won't of tha low speed at idlinE
speeds will produce very puneent
odor to the exhaust. Too rich mix
ture at high speed produces oiack
smoke at the exhaust ana 700 leaa G
through the carburetor. The high
speed adjustment is correct when the
engine family indicates backhrlnG
with retarded spark which disappears
when the spark Is advanced.
Other Causes at Fault.
When the above symptoms present
themselves, one should not jump at
conclusions and assume that the car
buretor adjustment is at fault. Tor
these conditions can also be set up by
mechanical defects. Any restriction
of the fuel flow through the carbu-
rotor will cause backfring and ir-
regular running: this is also true OF
air leaks at the manifold connections
or valve stems. A leaky float or
worm float valve will disturb the ad-
justment of the mixture, making 1t
more rich and thus cause sluggish
action of the engine. Wear In the
levers which connect the stranger
valve at the carburetor to the choke
or dash control will cause hard start
ing and rich mixture.
The carburetor adjustment may be
wrong, but this cannot be proven un-
til the engine is running; therefore.
fuel supply. Examine the rear tank
for gasoline. open the lower drain of
the vacuum tank and insert wire in
the opening if gasoline does not flow.
as sediment many times will clog this
outlet Next lift the float valve of
the carburetor for few seconds.
This systematic examination of these
units will prove the presence of fuel
in the float chamber and eliminates
the possibility of major troubles. per-
mitting an analysis of the minor de-
tails.-AutomobileD Digest.