Yamaha - Drive Sprocket 13 Tooth Drivetrain Component 9383A-13031-00. Overview. You can usually tell when a sprocket is starting to go-power feels uneven, and the drivetrain just doesn't sound right. I've replaced a lot of these where the wear wasn't obvious until you got under load. The Yamaha Drive Sprocket 13 Tooth 9383A-13031-00 helps bring everything back to smooth, predictable operation. It's a small part, but it keeps your drivetrain running the way it should.. Key Features. • 13 Tooth Gear Configuration - Provides proper gearing for balanced performance and control.. • Precision Tooth Design - Ensures smooth chain engagement and consistent power transfer.. • Yamaha Engineered Fit - Built to match factory alignment and mounting specifications.. • Supports Drivetrain Efficiency - Helps reduce wear and maintain smooth operation.. • Durable Metal Construction - Designed to handle load, friction, and long-term use.. Engine & Boat Compatibility. The Yamaha Drive Sprocket 13 Tooth 938