If you choose to execute adjustments to your Yamaha XS 650 SE then it is always a good plan to own a Workshop Manual to use as personal reference just in case you want to know tips on how to remove a certain component for example the Brake Discs and fit it again effectively.
Yamaha XS 650 SE Workshop Manuals offers clear specific diagnostic info for your car or truck so if something is faulty it will help you figure out what the issue is and the best way to repair it. After that you can analyse if this can be done yourself or if the job is too big it is possible to book your XS 650 SE in to a decent friendly mechanic.
Yamaha XS 650 SE manual