Patent ID: 8075356

Claim:
A marine vessel propulsion device, comprising: an engine to generate a driving force by combustion of a fuel by an ignition unit; a thrust generating unit driven by the driving force of the engine to generate thrust underwater; a shift mechanism unit capable of switching between a transmitting state of transmitting the driving force of the engine to the thrust generating unit and a cut-off state of cutting off the driving force of the engine from the thrust generating unit; a shift drive unit to drive the shift mechanism unit; and a control unit to electrically control the shift drive unit based on a position of a shift operational unit that is operated by a user to perform a shifting operation to a first shift position corresponding to the transmitting state, and a second shift position corresponding to the cut-off state; wherein the control unit temporarily lowers an engine speed by starting misfire control of the ignition unit when the shift operational unit is operated to change from the first shift position to the second shift position; and the control unit controls the shift drive unit, after a start of the misfire control, such that the shift mechanism unit starts switching from the transmitting state to the cut-off state after elapse of a first delay time period corresponding to an amount of time from a start of misfire control to a point in time when the ignition unit actually starts to misfire.