20200 14 & 18mm threaded spark plug thread chaser

Keeping spark plug threads clean is essential for preventing head damage and ensuring proper heat transfer. This double-ended thread chaser from Lisle is designed to clean up both 14mm and 18mm threads, making it versatile for a wide range of Harley engines and oxygen sensor ports. It is not a tap, so it will not cut new threads, but it will safely clear out carbon and corrosion. You can use it with a standard 13/16-inch or 21mm spark plug socket or wrench. This universal tool is a simple way to ensure your plugs seat perfectly every time you perform a tune-up or sensor replacement, protecting the integrity of your cylinder heads.