The denso u-groove spark plug for honda cb 400 n 1978-1985 is part of the latest collection from denso.Features: 100 percent pre-fired to ensure reliable operation copper core center electrode for superior thermal conductivity unique five-rib insulator reduces flashover and decreases voltage loss dual copper and glass seal bonds the center electrode and insulator together for a gas-tight seal. Original equipment in automotive applications specifications: center electrode projection: non-projected center electrode type: standard ground electrode shape: u-groove heat range: 24 hex size imperial: 11 16 hex size metric: 17.5 Mm hex size: 17.5 Mm 11 16 model: x24es-u product name: spark plug research value: finalized riding style: adventure touring dual-sport atv off-road snow street utv watercraft spark gap imperial: 0.028 To fit: honda cbx 550 f2 1982 european models honda cbx 550 f2 1983 european models honda cbx 550 f2 1984 european models honda cbx 550 f 1982 european models honda cbx 550 f 1983 european models honda cbx 550 f 1984 european models honda cb 400 n 1978 european models honda cb 400 n 1979 european models honda cb 400 n 1980 european models honda cb 400 n 1981 european models honda cb 400 n 1982 european models honda cb 400 n 1983 european models honda cb 400 n 1984 european models honda cb 400 n 1985 european models honda cb 750 f1 1974 supersport european models honda cb 750 f1 1975 supersport european models honda cb 750 f2 1976 supersport european models ...