2006-2010 Suzuki DF150 / DF175 4-Stroke Outboards Service Manual, Page 74Get this manual
ENGINE CONTROL SYSTEM
IGNITION SYSTEM
The ignition system used by the DF150DF175 is fully transistorized, electronic microcomputer timing advanced typeThis system is totally battery powered, with the ECM controlling all ignition timing functionsThe ignition system is composed of the ignition coil, spark plug and components for system control (ECM, sensor, switch etc When the ignition switch is "ON", battery voltage (12 V) is applied to the circuit as shown in the illustrationThe ECM determines the optimum ignition timing and duration of current flowing through the ignition coil primary winding based on the signals received from various sensorsThe ECM interrupts the base current of the power transistor inside the ignition coil thereby controlling current flow (ignition) to the primary winding of ignition coilIn this way, mutual induction high voltage occurs in the ignition coil secondary side and spark is generated