If you have to do maintenance for your Sachs ZZ 125 then it is usually a great idea to possess a Workshop Manual to use as a guide in the event that you want to know simple methods to strip off a particular part for example the Exhaust and fit it again successfully.
Sachs ZZ 125 Workshop Manuals provides exact diagnostic guides for the car so if something is broken it will help you figure out what the issue is and tips on how to resolve it. After that you can determine if you can do this by yourself or in case the job is too big you could make a booking for your ZZ 125 in with a local car garage.
Sachs ZZ 125 manual