ARCO NEW Original Equipment Quality Replacement Outboard Starter Mercury/Mariner 6-15 HP - 1986-1996, 18-25 HP - 1980-2003, 10-tooth drive gear, w/ 2 1/2" motor casing. Replaces Part Numbers: Mercury 50-893889T Mercury 50-8M0033984 Mercury 50-90983A1 Mercury 50-90983T1