2009 Yamaha F40 Outboard Service Manual, Page 43Get this manual
Engine control system Fuel injection compensations Warm up compensation Compensation after startup Compensation at deceleration Compensation at acceleration Intake air temperature compensation Corresponding sensor Thermo sensor Thermo sensor TPS, Air pressure sensor TPS, Air pressure sensor Air temperature sensor
First, injection end timing is set, and then injection start timing will be calculated according to the determined injection amountInjection end timing Each cylinder at BTDC 120 In the case of the non-synchronous fuel injection, upon detecting changes in signals that exceed predetermined level from the TPS or the air pressure sensor, the engine ECM simultaneously transmits injection signals to all the cylinders regardless of crankshaft angleIn the fuel injection cut off mode, fuel injection is cut off synchronizing with the engine speed control mode of the ignition timing controlSee "Ignition timing control" (2-6) and "Engine speed control" (28)