The Mount Holly news., 1919-04-15

prepared by the United States Depart
ment of Agriculture)
When an examination has shown
that good spark is being obtained at
the right time, the next step is to see
whether the engine is receiving the
proper mixture of fuel and air. Many
carburetors are made so that it is
easy to remove the cover and see
whether there is gasoline in the bowl,
and where this is possible it is the
easiest way to determine whether the
fuel supply is all right up to that point.
Other types of carburetor have tight
covers, but are equipped with small
petcocks, by opening which one can de-
termine whether a supply of fuel is
available.
If there is no fuel in the carburetor,
either the tank is empty or there is
some obstruction in the pipe line be-
tween the tank and the carburetor.
Water in Gasoline System.
To see that the carburetor contains
liquid which looks like gasoline,
however, is not enough, as water and
gasoline look very much alike, and 1t is
not at all uncommon for water to be
present in the gasoline system. Neith-
er does this water always enter the
system when it is being filled, as Is
generally supposed. 1t is often the re-
suit of condensation of moisture on the
sides Of the gasoline tank, which runs
down and settles at the lowest points
in the system. This may be in the
bottom of the carburetor, in the supply
pipe, or in the strainer, or settling
chamber. Where strainers or settling
chambers are provided, these should
be drained and cleaned frequently, es-
pecially in cold weather, when any wa
ter present may cause considerable
trouble by freezing.
For Removing Water.
A petcock on the carburetor is good
means for removing any water which
bowl of the carburetor, and which,
when present, will cause difficulty in
starting. When making a test in this
way, it is usually advisable to allow
enough gasoline to run through to
make sure that the carburetor has a
full supply, as sometimes a partial
stoppage of the pipe will allow small
amount of gasoline to get by into the
carburetor, but not enough to allow
4 the engine to start easily. Allowing
half-cupful Of fuel to run through it
eliminates this possibility. 1t is easy
to ascertain whether water is present
in the carburetor by catching in glass
bottle or tumbler the liquid which runs
| through when the petcock Is open. Any
water present will settle at the bottom
of the glass and thin line will be
visible between the water and the
gasoline.
Air Is Important.
1t is not enough merely to have fuel
| In the carburetor; it must be mixed
with the proper amount of air as it
is drawn into the combustion chamber.
It sometimes happens that the needle
valve is closed or stopped with dirt,
and that while there is fuel in the car
buretor none can get into the combus-
ton chamber. If the engine has pet
cock leading into the combustion
chamber, by opening this and crank
ing the engine a few times one
can tell by smelling the escaping air
whether gasoline is entering the cham
Der. The same result can be obtained
by smelling the exhaust when the en-
CINE Is turned over, or by removing
a spark plug, closing the hole during
the suction stroke and opening 1t dur
ing the compression stroke.
Make Enair.e Start.
By alternately opening and closing
the needle valve, first being careful to
note the original position so that 1t will
be possible to readjust it If necessary,
it is easy to see whether a different
mixture will make the engine start.
Or, when there is doubt whether
enough fuel is entering the cylinder, a
small quantity of gasoline (about a
teaspoonful) may be poured into the
combustion chamber through the prim-
ing cock or spark-plug hole and allow
ed to stand for minute or two to
vaporize and mix with the air before
crankiEg the engine. If then one or
two explosions occur and no more, it is
an indication that only the printing has
burned, and that fuel is not being fur
nished In sufficient quantity through
the carburetor.
Mixture Too Rich.
1t sometimes happens that too rich a
mixture of fuel and air enters the
combustion chamber, which is practi-
cally as bad as no fuel at all, as the
rich mixture cannot be exploded by
the spark. This does not often happen
with cold engine and with the grades
of fuel now on the market, but it is
not at all uncommon with warm en-
gine. There are several ways Of over
coming this difficulty. Closing the
needle valve and cranking the engine
few times will remove the rich mix.
ture quickly and replace 1t with prac-
tically pure air. Removing a spark