If you wish to do adjustments on your Veli KING50 EEC then it is usually a great idea to own a Workshop Manual to keep just for a guide just in case you want to know ways to remove a particular component for instance the Drive Shaft and install it again correctly.
Veli KING50 EEC Workshop Manuals will provide you with exact diagnostic wisdom for the car therefore if something is broken it will help you ascertain what the issue is and how you can repair it. You will be able to decide if you can do this yourself or in case the job is too big you could make a reservation for your KING50 EEC in to a trusted garage.
Veli KING50 EEC manual