Bike has been overheating since early August, several things had gone wrong:
1. Fan relay stuck on- replaced.
2.Temperature sensor on top of block failed- replaced.
3. Replaced thermostat*, inspected impeller in water pump.
4. Finaly, the real deal: Left radiator was fine; it flows very well. Right radiator is controlled by thermostat and was badly plugged! Flushed out and now flows same as the left one. History: Changed the coolant only every three years. My bad? Bike has 193k on it now.
* thermostat didn't need replacing, I believe that is called "flailing" (desperately replacing parts without a positive diagnosis). So, if you have been ignoring the cooling system for several years and a google miles, maybe you should flush the right radiator this Winter!