Suzuki DF25/DF30 Four Stroke Service Manual, Page 56Get this manual
ENGINE CONTROL 3-5
IGNITION TIMING CONTROL
Outline The ignition timing varies based upon engine speedThe CKP sensors monitor current engine speed and send signals to the CDI unitBased on this signal, the CDI unit determines the optimum ignition timing and supplies voltage to the primary winding of the ignition coil
CDI unit
Basic sensor CKP sensorInforms CDI unit of engine speed and crankshaft angleIgnition timing is determined by digital map designed in relation to engine speed