Shop by Brand Yamaha OutboardPiston/Piston Kit ; Piston Pin ; Piston Ring Back Piston Ring 66T-11604-00 0.25 Viewer:792 OEM No. : 66T-11604-00-0.25 For YAMAHA Outboard 40 HP You May Also Be Interested In Piston Kit 6R5-11635-01 0.25 Piston Kit 6R5-11645-01 0.25 Crank 6K5-11412-00-00 Piston Kit 3B2-00004-0/3B2000040M/3B2-00004-1/3B2000041M 0.50