The Washington herald., 1917-03-04
COMMON-SENSE MASTER
OF SPARK Plug Lever
Hints Given for Operation of Car by
Beginners.
New York Evening Post.)

New York Evening Post)
Possibly the hardest operation in the
handling of the car for the neophyte to
master Is the advantageous use OF the
spark control lever. The reason for this
Is that most beginners do not study the
matter carefully enough and bring little
common-sense to bear on it. Yet after
this control is once thoroughly mastered,
1t is one of the most useful and flexible
on the car
To begin with, the spark lever should
never be In the position known as dead
center for starting. When the spark is
so timed. there is danger of a Blackjack
with a broken arm and other pleasant
possibilities. This dead-center position
is easily determined In cars that have
battery ignition. In this case simply
remove one plug and lay it on any metal
part of the car, without removing the
wire. Turn on the current and the crank
until the piston reaches its highest posi-
ton in the cylinder. Next manipulate the
spark lever until the sparks occur at the
plug. when the position of the lever in
the quadrant should be marked with a
file. and for starting always see that the
spark is retarded past that point. When
the magnetic alone Is employed, the spark
may be advanced as far as you like, as
there Is no danger of a back kick in
starting on the magnetic.
MOVING the spark Lever.
OF course, every one understands that
| the moving of the spark lever simply
! changes the relative occurrence of the
spark in relation to the stroke OF the pis-
| ton. When the lever Is advanced, the
/ spark occurs sOoner-that is to say, ear
! lier in the stroke. If the spark is early
1t occurs before the piston has reached
! the highest point in its stroke. If the
spark is late, 1t occurs after the piston
/ has passed the top OF its stroke and start
ed down again. After the motor is rup.
ming. the spark should be advanced ir
proportion to the speed at which the en-.
gine Is running, but this does not NEAR
In proportion to the work the power plant
Is doing. With a fast-running engine. Il
| Is obvious that 1t Is necessary to begir
| igniting the gas before the piston reaches
! the top Of its stroke in order to get the
| combustion started in time to realize the
full force Of the explosion when the pis
ton is just reaching dead center and Is
ready to begin its downward Journey.
Use in Hill Climbing.
In actual operation the spark lever
should be fully retarded when starting
the motor, should be advanced about half
way when the car begins to gather head
way in low gear. and may be kept there
until the vehicle is In high gear. after
which the lever should be advanced to a
point Just below where knock occurs.
On the average car the spark lever may
be fully advanced when the speed gets
up to IS miles per hour or above. The
spark lever may be advanced quickly
when the motor Is running under light
load. but must be pushed forward more
slowly when the vehicle Is heavily load
ed In climbing hills the spark lever may
be retarded gradually as the car slows
down. When lower gears are thrown in
the lever may generally be advanced
again as the motor speeds up. This
phase OF spark control will be learned by
degrees as the driver comes to know his
car better and better.