If you have to accomplish maintenance to your Orion AGB 21F then it will always be a good plan to possess a Workshop Manual to use as a guide in the event that you need to know how to strip off a particular component such as the Exhaust and fit it again in the correct way.
Orion AGB 21F Workshop Manuals will provide you with detailed diagnostic info with regards to your vehicle so if something is faulty it can help you work out what the problem is and how to resolve it. You will be able to assess if you can do this on your own or if the job is too big you are able to book your AGB 21F in to a trusted repair garage.
Orion AGB 21F manual