5/16-18 Honda 8-30 hp, Johnson/Evinrude 6-30 hp, Merc/Mariner 8-25 hp, Nissan 8-18 hp, Suzuki 8-30 hp, Tohatsu 8-18 hp, Yamaha 8-25 hp. May fit other 2-strokes up to 30 hp with 5/16-18 bolts.