If you can find the appropriate BS manual* it shows how to reseat that jet, but the weapon of choice is a Briggs dip stick tube. The slightly chamfered end that pushes into the plastic seal in the sump of its intended use, pushes against the steel “ bellville” washer of the jet assembly and seats it into the carb.
* Single cylinder L head post 1981. Page 23. Publication 270962-12/03