Charging Circuit; Ignition Circuit Tests - Honda CB350 Repair Manual

112 ELECTRICAL SYSTEM
Ignition circuit components : (1) battery, (2) fuse,
(3) ignition coils, (4) points, (5) condensers, (6)
spark plugs
iron core. The primary winding has
200—300 turns of enameled copper wire
around the core, and the secondary wind—
ing about 10—20,000 turns of somewhat
finer wire around the core, and is con—
nected directly to the high—tension (spark
plug) lead.
When the ignition switch is turned on,
current from the battery flows through
the coil primary winding, and through
the points (assuming that they are closed)
to ground. As the engine is turned over
by the electric or kick—starter, the breaker
cam opens the points.
When the points open, the current from
the battery ceases to flow; the magnetic
field which this current had produced
around the coil's primary winding col—
lapses rapidly, and by the phenomenon
known as "electromagnetic induction"
an extremely high—voltage is produced in
the coil's secondary winding—suf—
ficiently high to jump an air gap and fire
the spark plug.
A condenser is wired in parallel with
each set of points to prevent the current
flow from jumping across them as they
are beginning to open.
CHARGING CIRCUIT
The charging system consists of the al—
ternator, rectifier, voltage regulator, and
the battery.
The alternator stator is comprised ofsix
windings of wire around the poles of a
laminated iron core. The rotor is a perma—
nently magnetized unit bolted to the left—
side of the crankshaft. As the engine
turns over, the magnetic field of the rotor
passes through the coil windings inducing
a current flow in them. The output is
proportional to engine rpm.
Alternator output is alternating current
(1)
4)
Charging circuit components: (1) alternator, (2) rec—
tifier, (3) regulator, (4) battery
which must be changed to direct current
in order to charge the battery. This is ac—
complished by a full—wave rectifier which
consists of four selenium or silicon di—
odes.
The voltage regulator maintains the
rectified alternator output at approxi—
mately 13—16 volts across the battery.
Any excess output is grounded by the
regulator.
Ignition Circuit Tests
1. Troubleshooting the ignition sys—
tem is made somewhat easier by the fact
that the components for the two cylinders
are completely independent.
2. If there is a no—spark condition at
both cylinders, the trouble will be in the
battery, fuse, or wiring connections.
Check the 15A fuse (located near the bat—
tery) first. If this fuse is blown, none of
the electrical components will function.
If the fuse is satisfactory, check the bat—
tery state—of—charge. Although a low bat—
tery may not operate the electric starter,
it does not require a very high state—of—
charge to spark the plugs, turning the
engine over with the kick—starter.
Check the battery terminal connec—
tions, then the ignition circuit connec—
tions, ignition switch, etc.
3. In the event of hard starting, mis—
firing, or cutting out, first check the car—
buretors. Be sure that the fault is elec—
trical before replacing any components.
Be sure that all connections are clean,
dry, and tight. Wiring plugs and connec—
tors often accumulate dirt or water, and
sometimes work loose. Check these first,
then proceed as follows: