If you want to accomplish adjustments on your own Yamaha WR 426 F then it is usually recommended to own a Workshop Manual for a reference should you need to know how to strip off a specific component including Brake Discs and match it again safely.
Yamaha WR 426 F Workshop Manuals offers clear unique diagnostic info with regards to your automobile therefore if something is faulty it can help you identify what the situation is and tips to fix it. You can then assess if you can do this on your own or if ever the job is just too big you can still book your WR 426 F in to a nearby mechanic.
Yamaha WR 426 F manual