If you choose to execute auto repairs on your Yamaha DT 125 R then it is always a great idea to own a Workshop Manual for a guide if you need to know the right way to strip off a certain component like the Brake Pads and match it again appropriately.
Yamaha DT 125 R Workshop Manuals are able to offer unique diagnostic info for your car or truck therefore if something is faulty it helps you determine what the problem is and tips on how to repair it. You can then determine if this can be achieved yourself or in case the job is just too big you could book your DT 125 R right into a nearby garage.
Yamaha DT 125 R manual