Prochem will only run with choke open

Finally have my TM moved over to my new van got everything set up and for some reason my machine will only run with the choke open ? It has been ran very few hours over the last 3 months mainly just cleaning a few area rugs. But still was working fine but for some reason it only runs with the choke open if I close it will die instantly.. anyone have any suggestions it would be greatly appreciated. Also unit is a Prochem legend se.
Thanks