Choke is easy to set, loosen the 3 screws,Flick the carb to wide open throttle (not running and when cold), turn the choke so it just closes, then fire up the truck with the choke closed. quickly do a rough set on the high idle screw. Turn truck off, let cool and try it again till you have it run at 1200-1300 rpm when if first fires up.then flick the excelarator to drop it out of high idle and adjust to low idle speed