If you choose to undertake auto repairs on your Sym GTS 125 then it is always a good idea to have access to a Workshop Manual for personal reference just in case you need to know the right way to take off a particular part much like the Door and fit it again the right way.
Sym GTS 125 Workshop Manuals can provide specific diagnostic wisdom on your automobile therefore if something is faulty it helps you identify what the problem is and tips on how to correct it. You can then analyse if you can do this on your own or if ever the job is simply too big you are able to make a reservation for your GTS 125 in with a nearby repair garage.
Sym GTS 125 manual