I have a 1977 Mercury 50 hp with the mercontrol with the choke button on the top of the control box. My question is do you hold that button in while cranking the motor? Or do you press it once and then crank the motor? I realize you need to lift the throttle lever. I'm used to the choke built into the key where you push in and crank. I'd assume you would hold the button in while cranking, just want to make sure. Any help would be greatly appreciated.