Home › Forum › Ask A Member › Correct spark plug for 1924 Model D Elto Ruddertwin › Re: Correct spark plug for 1924 Model D Elto Ruddertwin
April 4, 2018 at 1:54 am
#73430
NGK does makes equivalent sized plugs, their A-6, A-7 and A-8 (or AB-6, AB-7, AB-8, if you want a conventional 13/16" hex, rather than 1") are 18mm, 1/2" reach, with 6 the hottest and 8 the coolest in their heat range.