BRIGGS AND STRATTON 691764 HOSE CONNECTOR
First, if using a dipstick remove it from the cap. Determine the best location to drill a hole using a letter Q drill bit. Since you’re working with plastic, it may also be possible to use a 21/64" or 5/16" bit too. Next, tap the whole with a 1/8" NPT tap, install the barb, epoxy in place and you’re finished.