If you wish to conduct repairs for your Sym GTS 250i then it will always be recommended to own a Workshop Manual for personal reference in case you need to know how you can take off a certain part for example Dashboard and install it again in the correct way.
Sym GTS 250i Workshop Manuals offers clear special diagnostic wisdom on your automobile so if something is playing up it can help you determine what the issue is and how you can correct it. You can then analyse if this can be done by yourself or in case the job is just too big you can book your GTS 250i right into a nearby repair garage.
Sym GTS 250i manual