JT 13/48T Front & Rear Sprocket Kit

Pair a durable chromoly steel countershaft sprocket with a lightweight blue RaceLite rear sprocket for the Yamaha applications listed above. The JTF565.13SC front features self-cleaning grooves, while the JTA251.48BLU rear uses 7075-T6 aluminum construction for a lightweight racing application.

This two-sprocket package provides a 13/48 tooth combination for a 520-size drivetrain. The blue anodized rear adds a coordinated finish, and the selected ratio lets you maintain or change your gearing according to your model's original specification and riding requirements.

Critical Fitment Warnings

• Confirm the ratio: this kit always supplies 13 teeth front and 48 teeth rear. For example, JT lists 13/51 stock gearing for the 2026 YZ450F, so this kit changes that model's final drive ratio.
• Model identification: YZ250 and YZ250X entries refer to the 2-stroke models. Use the model and year table above to confirm your application.
• Chain compatibility: use a suitable 520 chain. Verify chain length, adjustment range, alignment and guide clearance for the selected tooth counts.
• Drivetrain condition: inspect the chain, sprocket mounting surfaces and retaining hardware. Replace worn components before use.
• Torque specifications: follow the Yamaha service manual for your exact model year when tightening sprocket fasteners and securing the countershaft retainer.