https://www.yamahapartshouse.com/oemparts/a/yam/5003aebff8700212fc83c047/side-cover

Part 15; Screw, Truss Head Tapping 97707-50012-00

https://www.amazon.com/Yamaha-97707-50012-00-SCREW-TRUSS-977075001200/dp/B005C5EB80

here are two on amazon for 6 dollars