Sierra 18-6420 Outboard StarterSierra replacement outboard starter for Yamaha Outboards. Sierra aftermarket starters are manufactured to meet or exceed all OEM requirements. For Yamaha 9.9 (1984-97), 15 (1984-97), 20 (1996-97), 25 (1988-09); 10 Tooth drive gear; Interchangeable with: Arco; 3421; Hitachi; S106-07B; S106-07E; S106-07F; Yamaha Outboard; 682-81800-11-00; 682-81800-12-00; 6L2-81800-10-00; 6L2-81800-11-00; 6L2-81800-20-00;