Patent ID: 7163000

Claim:
An engine comprising a throttle valve configured to adjust an amount of air supplied to the engine, an operating member, an operation amount detecting device configured to detect an operation amount of the operating member, a motor configured to drive the throttle valve between open and closed positions according to a detection value detected by the operation amount detecting device, a throttle opening detecting device configured to detect an opening of the throttle valve, a limp-home mechanism configured to keep the opening of the throttle valve in a mechanically neutral position when an abnormality occurs in which a normal throttle opening control for the throttle valve is not available, an ignition timing control device configured to switch an ignition timing control for the engine from a regular ignition timing control to a limp-home ignition timing control conducted according to an amount of intake air with the opening of the throttle valve in the mechanically neutral position when the opening of the throttle valve is in the mechanically neutral position due to occurrence of the abnormality, and an ignition timing control changing device configured to change the ignition timing control stepwise through a plurality of steps over a predetermined time period, when the ignition timing control conducted by the ignition timing control device is switched from the regular ignition timing control to the limp-home ignition timing control.