Out at Folsom Lake, CA Dec 10th 2011. Checking work on Bassett spider line jets. Drilled and tapped -8 an fitting to 7/16 20 threads and drilled stainless steel set screws as water inlet jets. Helped with water flow. Video looking out the back while cruising 3000 rpm and at idle.
https://www.ultimatehandyman.co.uk/ shows you how to tap a hole using a cordless drill and a taper tap. This is useful if you have a lot of holes to thread, or if you require holes tapping quickly.