8-1-1
PRfNCIPLE
OF
THE
OPERATION
1)
Rotation
of
the flywheel generates
a
voltage
on
the primary side
of
the ignition device.
By this voltage, electric current
(11)
flows
and it charges condenser.
2)
With further rotation
of
the flywheel, electric current
(h),
which is reversed of electric current
(h),
flows
through power transistor base terminal
(B).
This actuates power transistor and results electric
current
(b)
and
(14)
in
signal transistor. The current
(14)
charges the condenser reversely as the current
11’
did.
3)
With further move rotation
of
the flywheel, the current generated by primary coil starts to decrease
as
it
passes its peak. Current
(Is)
starts flowing because there is
no
electric potential difference in the
C
(collector) and
E
(emitter) Terminals of signal transistor. Current
(Is)
flows into the gate
(G)
of
SCR
which induct SCR.
This
current change causes high voltage on secondary coil which produces sparks at spark plug.
4)
Current
(h)
turns into current
(16)
with induction
of
the
SCR,
this cuts
off
anent
b
abruptly.
Fig.
8-2
8-2
IGNITION
SYSTEM
CHECK
In
the event of malfunction of the ignition
system,
check the following first:
Broken, frayed, loose
or
disconnected ignition wires.
Faulty spark plug-wet, dirty, insulation broken
or
incorrect plug gap.
If difficulty
is
experienced in starting the engine or if engine misfires,
the
strength
of
the ignition spark
should be checked
:
Remove spark plug-then with the ignition cable connected to it, lay the spark plug
on
a
convenient metal
part
of
the engine
so
that the gap can be observed as
you
rotate the crankshaft several times by means of
the recoil starter.
If
a good strong spark occurs, the ignition system
can
be eliminated as the source
of
trouble.
If
there is
a
weak
spark or no spark at all, check the ignition system as follows:
1)
Check to make sure that the external magnet, mounted
on
the flywheel is in a good condition.
2)
Since the solid state ignition unit
is
self-contained, the only testing which
can
be performed
is
on
the
Using a
good
quality ohm-meter, check the secondary coil resistance between the plug terminal of
the
ignition lead and the engine stop switch wire.
This resistance reading should
be
approximately
10,000
to
12,000
ohms.
If
the
resistance reading
is
infinite, this indicates open winding in the ignition unit, a loose
or
broken spark plug connector or
a
If
a
very low reading
is
taken,the secondary coil
is
probably shorted.
If,
after testing, the ignition unit
itself is determined to
be
faulty, then it will
have
to be replaced.
secondary coil resistance..
0
failed high tension lead.
-
37
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