To provide an engine provided with a choke valve gear that is able to perform a valve opening action automatically even in such an engine with no battery.

A gasoline engine 1 is equipped with a choke valve 2, and in addition, it is also provided with a power circuit part 12 obtaining the specified voltage from an engine generating coil 11, a temperature sensor 20 detecting a temperature of engine exhaust gas, an actuator 21 being driven by voltage of the power circuit part 12, and controlling an opening in the choke valve 2, and a control part 22 controlling this actuator 21 so as to make the choke valve 2 into a state of being opened in response to such a case where the temperature detected by the temperature sensor 20 is more than the setting temperature, respectively. At a time when the engine 1 is started, the choke valve 2 is made into a state of being manually closed, starting the engine 1 and, after engine starting, the choke valve 2 is made into a state of being opened as in time of ordinary driving at a time when the detection temperature of the control part 22 has become more than the certain setting temperature.