If you have to perform repairs on your Yamaha TT R90 then it is usually a great idea to own a Workshop Manual for reference in case that you need to know how to remove a certain part for example, the Brake Pads and match it again in the correct way.
Yamaha TT R90 Workshop Manuals offers clear distinct diagnostic information on your automobile so if something is playing up it will help you find out what the situation is and how you can fix it. After that you can assess if you can do this on your own or if ever the job is too big you can actually make a reservation for your TT R90 right into a decent car garage.
Yamaha TT R90 manual