DSK Hyosung — excessive heating of engine

I am owner of aquila gv250. The only problem i am facing is heating issue of this air cooled engine. It gets super hot within 5-6 km on open road and within 10 min on traffic road. Its almost impossible to ride a bike for 50km without a half hour stoppage to cool down and this bike falls under cruiser segment.

If this is the common issue then its my mistake that i bought this bike and if its an issue, i like to get this fixed.