If you wish to perform fixes on your own Yamaha YZ 125 then it will always be a good plan to possess a Workshop Manual for personal reference if you want to know methods to take off a particular component for example the Door and install it again the right way.
Yamaha YZ 125 Workshop Manuals provide you with special diagnostic info with regards to your automobile so if something is faulty it will help you work out what the problem is and ways to resolve it. Then you are able to assess if this can be done yourself or in the event the job is too big you can actually make a booking for your YZ 125 in to a suitable friendly mechanic.
Yamaha YZ 125 manual