Evening star., 1924-08-17
No. 5s.-The Firzt Long Mile.

In spite OF all advice to the con-
trary, Smith insisted upon racing his
motor after cranking it the other eve
ming. The machine had been stand
ing out in the open for Ave hours
and was naturally cold. ! warned
him that he was doing a very unwise
thing. but he paid no attention to me.
That Is, not until the next day.
Along about lunch time he confessed
that he had heard a very pronounced
knock in the motor when driving to
his once. He wondered what on
earth Ii could be, and. particularly,
what on earth could have caused it.
1t is strange how so many car owners
puzzle over the obvious.
AS explained to him, the first mile
car travels after it has been idle is
the most trying of it's whole days
run. Nine-tenths of all engine trou-
BILE originates during this first plunge
into service, though the trouble may
not manifest itself until the driver is
miles from the nearest garage. II
motors could air their views IN
words. they would unGuestionably
toll us that while it's nice to crank
up in the morning, it's nicer to stall
instead.
Reason for Care.
when the lubricants, the metal and
the water are stone cold, the engine op-
crates at disadvantage, i said.
The trouble begins the moment the
ignition switch is on and does not end
until the first puff of warm air blows
UP under the dash. Many drivers
imagine that because there is plenty
of lubricant in the crankcase the en-
gine bearings are soaked in oil. But
such is not the case. The main bear
ings of the crankshaft. as we'll as
the connecting rod bearings, are so
tightly adjusted that only the thin
nest film of oil can remain between
the bearing surfaces. There may be
particles of dirt in this oil Even II
it is clean and new, II will be more
or less congealed after the car has
been standing.
II the machine has been standing
out in cold weather, this film of oil
will become gummy and the remain
der of the oil in the crankcase will be
hardened. and thus flow very slowly.
All this means that the bearings will
not be sufficiently fabricated when
the engine makes it's first several
thousand revolutions. To burn out a
bearing. therefore, it is only neces-
sary TO race the motor an instant or
two as you did last evening"
Avoiding the Stall.
But if I don't race the motor it
will STALL" Smith argued. II want to
do the right thing. but is the right
thing in this case practical?"
IF your engine stalls incessantly
after you have cranked it, either you
do not operate the choker properly
or your carhuretor needs adjusting
for a richer mixture. Perhaps you
make the mistake of thinking that a
lean mixture gives greater mileage.
If so. you should remember that you
are going to Offset any economy re-
sulting from a lean mixture by chok-
ing the carburetor excessively when
you are trying to warm up the motor.
Before trying a richer mixture.
check over your method OF operating
the choker. See II you pull it all the
way out when you start cranking.
Note whether you push it half way in
when the motor has started and then
pull il slightly farther out or push it
slightly farther in, depending upon
whether the engine threatens to stall
for want Of gas or for want of air
1t is easy to tell which. II the engine