Replace or upgrade your worn chain and sprockets with this market leading sprocket kit featuring quality JT Sprockets and D.I.D chain brought to you by THS Moto. Note the chain may need to be adjusted to length using a chain breaker tool. This Sprocket Kit contains a 13 tooth front JT sprocket and 51 tooth rear JT sprocket with a 520VX3114 114-Link 520VX3 FJ X-Ring Solid Bush clip DID Chain Fits: Yamaha WR250F 2020-2021 YZ250F 2010-2013 YZ250FX 2015-2021