Re: Correct spark plug for 1924 Model D Elto Ruddertwin Home › Forum › Ask A Member › Correct spark plug for 1924 Model D Elto Ruddertwin › Re: Correct spark plug for 1924 Model D Elto Ruddertwin jimrossReplies: 16Topics: 2 April 8, 2018 at 1:15 pm #73606 There may be a fine line between correct, original and best but those of us who have collected and run the Elto’s have always sworn by the Champion D9J for Ruddertwin, all Speedsters and ’28 Quads. The original was the Champion 7. Jim Ross