2009 Yamaha F40 Outboard Service Manual, Page 41Get this manual
Engine control system
Ignition timing control
The CDI system of the engine ECM controls the ignition timingsIt determines the optimum ignition timing using the signals transmitted from the sensors and supplies the primary current to the ignition coils
Air pressure sensor Air temperature sensor TPS Thermo sensor Pulser coil Engine start switch Engine shut-off switch Oil pressure switch Neutral switch Engine ECM