IGNITION
TIMING
The ignition timing is preset at the factory and is not
adjustable. For troubleshooting purposes, it is possible
to make an approximate check of the ignition timing
using reference marks on the blower housing and
flywheel (Figure
2).
This check can be performed by a
continuity test.
M-1675
FIGURE
2.
IGNITION
TIMING
MARKS
Continuity Test
1.
Pull spark plug wires
off
spark plugs and remove
spark plugs.
1-1
Accidentalstarting of the engine
AWARNING
can result in severe personal
injury or death. Remove spark plugs before
proceeding.
2.
Turn ignition on.
3.
Connect
a
voltmeter between the negative
(-)
coil
terminal (larger diameter
of
the two threaded posts)
and a good engine ground.
~WARN~NG
The electronic ignition produces
current which can cause elec-
trical shock.
Do
not touch electrical components
or wires while ignition is on.
4. Rotate the flywheel slowly by hand in the clockwise
direction until the voltmeter reading switches from
approximately
1
volt to battery voltage. Atthis point,
one of the chaff screen screws should lie between
the two timing marks on the blower housing.
To
recheck timing, the flywheel must be rotated another
complete revolution in the clockwise direction.
Moving the flywheel back and forth across the
reference timing mark will not activate the electronic
ignition control.
5.
Install spark plugs and wires.
IGNITION
COIL
To test primary and secondary windings within the
ignition coil first make sure the ignition power is
off
and
coil is at room temperature of
7OoF
(21
"C).
1, Use a Simpson 260
VOM
or equivalent.
2.
Place a black lead on negative
(-)
coil terminal and
red lead to positive
(+)
coil terminal. Primary
resistance should read between 2.90-3.60 ohms.
3. Change resistance setting on ohmmeter. Place
ohmmeter leads inside of spark plug cable holes
(Figure
3).
Secondary resistance should read
between 14,500-1
9,800
ohms.
4.
If
either
of
the above resistances are not within
specification, replace coil.
FIGURE
3.
COILTEST
8-2
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