If you buy one from a wholesaler or lawn equipment dealer, it will have a funky plastic choke to throttle interlock. These come on every WJ-71 I have seen. You just break away the plastic parts and you're good to go. There will also be a spring on the choke shaft that needs to be removed.
AFAIK, all RC engine companies just remove these parts before installation of the carb on the various engines. Point is, don't be alarmed when you see something on the carb that doesn't belong on an RC engine.
You can buy the carb from DA with the choke parts pre modified and a very nice throttle arm. Many choices .... I just buy from Ebay and enjoy the lower price and free shipping.