Since you live in Karachi, there is a very good mechanic at Nazimabad near underpass (petrol pump wala). Name is Shahid (0345-2514119) and its workshop is little ahead of Eid gah ground in the service lane. A big Honda red board is displayed.
I know him myself for last 2 years he is very skilled Honda specialist.
When I used to own Star DL70, I got to know him and since that day I was getting some good quality tunning and the best fuel average.
You may contact him and try a tunning from him. There is no harm in it.