If you want to undertake adjustments on your own Yamaha XT 500 then it will always be recommended to have a Workshop Manual to keep just for a reference just in case you need to know ways to strip off a particular part such as the Gearbox and fit it again in the correct way.
Yamaha XT 500 Workshop Manuals can provide distinct diagnostic wisdom on your vehicle therefore if something is faulty it can help you find out what the issue is and how to make it better. Then you are able to assess if this can be done yourself or in case the job is too big you can book your XT 500 into a nearby mechanic.
Yamaha XT 500 manual