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Fig. 11
MAGNETO TIMING
When timing
or mounting
the
magneto,
the piston must
be
on
top dead center, which is accomplished when
U1e marked air vane on the flywheel
registers with
the
mark on the vertical centerline of
the flywheel
air shroud.
This
mark is visible when
the flywheel
air screen is
removed.
See Fig.
15.
Place coupling drive disc on the lugs of the magneto
drive shaft of
the
engine.
The drive
lugs
on
the
mag-
neto should then be turned counter-clockwise until
they engage
the impulse, In turning
the
drive lugs
counter-clockwise,
it
will
be
found that
a
point
of
considerable
resistance is met. This
is the point at
which the impulse is contacted and it
wi
11 be
found
that the lugs on the magneto will
now
line
up with
slots in
the
coupling disc. The magneto should
then
be
secured
to the pad with the two capscrews
and
lockwashers provided and these should be drawn
down loosely. Before tightening the
screws,
the mag·
neto must be lined
up
as nearly as
possible
on
the
same center
line as the
rna gneto
drive shaft.
The purpose of
the
coupling disc is
to
take care of
slight misalignment
which
may exist,
but it
is
very
important that this misalignment be kept at a min·
imum.
If
it is not,
wear
on the coupling will be
quite
rapid. The d i stance across the coupling slots is
slightly
more
than
the distance across the
lugs
on
the drive shaft by 1/8".
When
th1s clearance
is
equal-
ly divided, there
will
be about
1/16•
clearance
on
each
side
of the
disc.
Sec
Fig.
12.
An
alignment
Ml-215
MAGNETO
DRIVE lUG
1 16"
Fig. 12
COUPliNG
DISC
INSERT
HOOK END
OF
OAUGE HERE
78864C
10
Fig. 13
77519C
gauge
may be made
out of
a piece
of
1/16" thick
metal. To get the exact
alignment
insert the hook end
of
the gauge into the
side
clearance
slot.
Then
swing
the magneto in the direction which will tend to pinch
the
gauge in
this slot and tighten the m
o
u n t i n
g
screws.
See
Fig. 13.
In
order
to recheck the
timing,
the
crankshaft
should be turned
over
in a clockwise
direction when facing flywheel
end
and
it
will
be
noted
that the impulse coupling in
the
magneto
will
snap
when the
' D. C.'
marked vane on
the flywheel,
registers with the
mark on
the
vertical centerline of
the flywheel
air shroud.
If the impulse coupling
snaps
before
or
after the
marked
vane reaches the
top, the
magneto
drive
shaft cover
should be removed
and
the gears
should be checked to see
if the Timing
mark on
the
magn~to
gear lines up with the
mark on
the camshaft gear.
See
Fig. 34.
A
spo
rlc
oc/vonce
o
f
25°
is us
ee/.
SPARK
PLUG
The
spark
plug gap
should
be
maintained at
.030•.
Approximately every
100
hours
of
operation,
the plug
should be removed and
inspected.
The spark plug
points
should
be
scraped clean and
the plug thorough-
ly washed in alcohol. To set the points, a spark plug
wrench
or
any similar tool
should
be used.
See
Fig.
14.
If the porcelain insulator is
cracked,
replace with a
new plug of
cor
rect heat range, like
Champion
ID-16,
Fig.
14
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