Gravely 424 - Ignition Timing

IGNITION TIMING
PROCEDURE
Engines
are equipped
with
a
timing
sight
hole in either the bearing
plate
or in the
blower
housing.
A
snap but-
ton
is
used
to
cover
the
hole. The
button is
easily
pried
loose
with a screwdriver
so
that the
timing marks can
be
observed.
Two timing
marks
are stamped
on the
fywheel
-
the
T
mark
in&cates
Top Dead
Center
(TDC)
while
the
S
or
SP mark
indicates
the
spark or Spark
Rua
point which is
20"
before
top dead
center.
36=
Figure
7
-
Adiusting Breoker
Point
Gop
METHOD
f
-
STATIC
TIMING:
Remove
breaker
point
cover and
remoke
spark
plug
lead to
prevent
unin-
tentional starting.
Rotate engine
by
hand in
direction of normal
rotatiqn
(clockwise
when
viewed from
front
or
flywheel end).
Points should
just
begin
to break
as
the
S or
SP mark
appears in &e
center
of
the
timing
sight
hole.
Continue rotating engine
until
poiats
reach
maximum opening.
Measure
gap
with
feeler
gauge
-
gap
should
be .020
fully
open.
If neccssary,
loosen
point
gap
adiustment serew
and readjust
gap
to .020"
full
open.
Maxi'
mum
gap
setting
can vary a few
thousandths
l.OL&.On")
to achieve
smoothest running
Securely
tighten
adjust'
ing screw after
timing. This
provides
a method
of
timing in order
to start the engine
after
replacing
the
points.
Precise
timing
with a timing
light
is negessary.
METHOD
2
-
TIMING
LIGHT: Several
di$erent types of
timing
Iights ardavailable
-
follow
manufacturer's
instructions
for type used. The
lollowing
timing
procedure
can
be used with most timing
lights:
A.
Remove high
tension
Iead at spark
plug
-
lvrap
one end
of a short
piece
of
ffne wire
around
spark
plug
ter-
minal.
Reconnect Iead
to
terminal
-
free
end
of
wire must
protrude
from under
boot.
(Note:
Step
A for timing
lights
with
alligator elips
-
some
lights have sha4r
prongs on
spark
lead
-
on
these
simply
push prong
thru
boot until
it
rtntacts metal
connector.)
L2