If you need to execute fixes for your Kymco 150 Grand King then it is always a good idea to own a Workshop Manual to keep just for personal reference in the event you need to know easy methods to take out a specific component for example the Door and fit it again successfully.
Kymco 150 Grand King Workshop Manuals are able to offer detailed diagnostic guides for the vehicle therefore if something is faulty it can help you ascertain what the problem is and ways to resolve it. Then you are able to determine if this can be done yourself or in the event the job is just too big you can actually book your 150 Grand King right into a trusted friendly mechanic.
Kymco 150 Grand King manual