If you mean the resistor connected between the base of the transistor and the Arduino pin, then 1K (giving base current around 4mA) is rather high given that you are switching 240mA. I would use 220 ohms (base current around 18mA).
If you mean the resistor connected between the base of the transistor and the Arduino pin, then 1K (giving base current around 4mA) is rather high given that you are switching 240mA. I would use 220 ohms (base current around 18mA).