IGNITION
SYSTEM
The ignition system consists
of
the distributor, the coil, the
spark
plugs
in
the
engine
cylinders, the ignition switch
and
some source
of
electric current which
in
your truck
is
the
storage
battery.
The
purpose
of
the ignition system
is
to
provide
an
electric
spark
at
the
spark
plugs
at
the correct time to ignite the combustible fuel mixture
in
the cylinders
for
running the engine.
The
operation
of
the engine
of
your truck will
be
seriously
affected
if the distributor contact points
and
spark
plug
gaps
are
not
kept
properly
adjusted
and
the ignition correctly timed. The
results
of
improper
ignition
are
sluggish engine
performance,
poor
pickup
and
excessive fuel consumption.
DISTRIBUTOR
CONTACT POINTS
Improperly
adjusted
contact points
will
affect
ignition timing
and
engine
operation.
Before attempting
to
check
or
adjust
the contact
points to a
feeler
gauge,
the engine should
be
turned sufficiently
to
bring the
bre
'
aker
arm
in
contact with the
peak
of
a
lobe
on the
distributor cam. Due to the
passage
of
primary current across the
contact
points,
ci
normal transfer
of
metal from
one
point to the
other
may
cause
the
surface
of
the points to become slightly rough
or
pitted. Such roughness
must
be
removed
with a fine file
or
hone
before
the points
can
be
accurately
adjusted
to a
feeler
gauge.
The
points
should
open
.020
inch.
The adjustment
is
made
by
loosening
the
breaker
point
plate
locking screw
and
turning the
breaker
point
plate
adjusting screw
until
the
proper
gap
is
obtained.
IGNITION TIMING
The timing should
be
set
so
that
the distributor contact points
just
start
to
open
for No. 1 cylinder when the piston
is
on
top
dead
center.
(T.D.C.)
In
low altitudes with
standard
brands
of
non-premium gasoline,
the engine
will
give
its
best
performance if timed
at
standard
setting.
With this timing,
there
will
be
a
trace
of
spark
knock when
accelerating
with
wide
open
throttle.
When
using lower
grade
fuels,
or
after
carbon
has accumulated,
spark
knock may.
be
excessive with
standard
setting.
In
such cases
the ignition
should
be
retarded
not to
exceed
4
degrees
late
of
standard
setting.
36
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