did you go for complete overhaul.
for maintenance:
1. make sure t-valve is installed, fan is auto, auto choke works.
2. USE 10w40 api sg or sj oils. DONT use api sl sm, sn
some recommendation:
a. Suzuki Genuine Oil PREMIUM 10w40 API SG
b. Caltex Havoline 10w40 API SJ (newly launched)
c. Kixx Gold SJ 10w40
d. PSO generator oil 10w40
3. Get it properly tuned from 3s center or expert mechanic.\
4. Use good quality filters (Guard).
5. change oil at 3000 km or 3 months, whichever is earlier
Mileage is pretty good for carburetor cultus or is it efi?