Ignition System - Suzuki DF300 Service Manual

IGNITION SYSTEM

The ignition system used by the DF300 is a fully transistorized, electronic microcomputer timing advanced
type.
This system is totally battery powered, with the ECM controlling all ignition timing functions.
The ignition system is composed of the ignition coil, spark plug and components for system control (ECM,
sensor, switch etc.)
When the main switch is "ON", battery voltage (12 V) is applied to the circuit as shown in the illustration.
The ECM determines the optimum ignition timing and duration of current flowing through the ignition coil pri-
mary winding based on the signals received from various sensors. The ECM interrupts the base current of
the power transistor inside the ignition coil thereby controlling current flow (ignition) to the primary winding of
ignition coil.
In this way, a mutual induction high voltage occurs in the ignition coil secondary side and spark is generated.
+12 V
Ign.2
Spark
plug
+12 V
Ign.4
Spark
plug
+12 V
Ign.6
Spark
plug
+12 V
Ign.1
Spark
plug
+12 V
Ign.3
Spark
plug
+12 V
Ign.5
Spark
plug
ENGINE CONTROL SYSTEM
ECM
O
75
IGT1
Bl
74
IGT2
Gr/Y 73
IGT3
Lg/R
46
IGT4
W/G 47
IGT5
Bl/Y
IGT6 40
Ignition coil
GND
IGT
3-25
+BAT