JT/PBR Chain Kit 520HDS 13/49 Standard - Ultra-Light Rear Sprocket for YAMAHA YZ 125, YZF 250 2002-2027

JT DRIVE CHAIN offers this chain and sprocket kit for YAMAHA YZ 125, YZF 250 2002-2027. The front sprocket, on the gearbox output, drives the chain, which turns the rear sprocket bolted to the rear wheel.

Why replace the whole kit?

The benefits:

• A worn chain damages the teeth and worn teeth damage the chain: replacing all three parts together avoids ruining a new part within a few rides.
• Pitch, tooth counts and chain length are already matched: one order for the whole final drive.
• You can adapt the gearing: more teeth on the rear sprocket (or fewer on the front) gives more acceleration but less top speed; fewer teeth on the rear does the opposite.

When should you replace this part?

Hooked or pointed teeth, a chain that lifts off the back of the rear sprocket when pulled, tight spots or slack that needs adjusting every ride: the kit is worn out.

Specifications and fitting tips

• Front sprocket version: Standard
• Rear sprocket version: Standard
• Rear Sprocket Material: Aluminium
• Manufacturer part number: 3037901

Cross-Mania tip: Align the rear wheel (same marks on both sides), tighten the rear sprocket bolts to the specified torque with threadlocker, set the slack to the manual and recheck it after the first ride.

Compatibility

Check the exact model and year of your bike in the list below before ordering.

Fits:
YAMAHA YZ 125 2027
YAMAHA YZ 125 2026
YAMAHA YZ 125 2025
YAMAHA YZ 125 2024
YAMAHA YZ 125 2023
YAMAHA YZ 125 2022
YAMAHA YZ 125 2004
YAMAHA YZ 125 2003
YAMAHA YZ 125 2002
YAMAHA YZF 250 2008
YAMAHA YZF 250 2007
YAMAHA YZF 250 2006
YAMAHA YZF 250 2005