If you wish to undertake maintenance for your Veli ZQ 150 4 II then it will always be a great idea to have access to a Workshop Manual to use as reference in the event that you want to know the best ways to strip off a particular part including Gearbox and match it again adequately.
Veli ZQ 150 4 II Workshop Manuals are able to offer identifiable diagnostic details with regards to your automobile so if something is broken it will help you figure out what the issue is and some ways to correct it. You will be able to determine if this can be achieved on your own or if the job is just too big it is possible to book your ZQ 150 4 II into a trusted garage.
Veli ZQ 150 4 II manual