Yamaha - Oil Pump Cover Engine Protection Component YA2-63640-01-11. Overview. Oil system components don't get much attention until something goes wrong, and I've seen a simple cover cause bigger issues when it's worn or not sealing right. Keeping the oil pump protected and properly enclosed is key to long-term engine health. The Yamaha Oil Pump Cover YA2-63640-01-11 helps keep everything sealed, clean, and functioning the way it should. It's a small but important piece that supports the whole l