If you have to accomplish fixes for your Yamaha DT50X then it is always recommended to own a Workshop Manual to keep just for personal reference just in case you need to know the best ways to take off a particular component such as the Brake Pads and match it again in the correct manner.
Yamaha DT50X Workshop Manuals will provide you with special diagnostic guides for your car so if something is broken it will help you understand what the issue is and the way to resolve it. You can then decide if this can be done by yourself or in the event the job is too big you are able to book your DT50X right into a nearby car garage.
Yamaha DT50X manual