Description
This NGK 5666 spark plug is designed for use in gasoline engines and features a threaded stud terminal configuration. It has a heat range of 8 and an electrode tip made of nickel alloy. The spark gap is set at 0.035 inches and the hex size is 16 mm metric and 5/8 inch imperial. The thread reach is 19.1 mm metric and 3/4 inch imperial. The spark plug is styled as CR8EH-9 and has an electrical resistance of 5k Ohms. This spark plug is suitable for use in a variety of motorcycle and scooter models.




