You need to describe better what hapened to the choke. Did the engine swallow it? If so dial 1 800 I need an engine. You can choke it with your thumb and you will need to choke your engine to start it. If the choke butterfly is still inplace make sure the ball and spring will keep it from closing in flight. Take the carb to a saw shop, they usually have a box of old carbs to scrounge parts off.