We get so many questions concerning the cooling system and its operation.
Here's the scoop:
The normal temperature at cruising speed is between 60-80 depending on your weather.
Normal temperature in stop & go traffic can cycle between 80 and 100.
At 100 degrees (+/- a few) the cooling fan will turn on, and temperature will drop to about 80. The fan will cycle off, and the temperature cycle will continue as long as you stay stopped & idling.
This is all prefectly normal and within the normal operating limits of the engine.
Common oddities with cooling systems:
If you experience boilovers without excessive temperatures, make sure that the radiator cap is properly seated, and make sure it holds pressure. You may need to get that tested by a shop.
If your temperature exceeds 100 by a large amount (or you can see the fan is not running properly) check to make sure the fan switch is connected (on thermostat housing), the fan itself is connected (plug is above the ignition coil mount), and the fan is good. Make sure all fuses are good as well.
If you see an erratic temperature reading or a needle below 60 reading (with engine running at normal temperature), make sure that you have sufficient coolant in the system. Verify that there is fluid in the coolant overflow bottle (located onthe right hand side of the bike, under the tail fairing). If level is correct, chances are good you have a bad connection on the temperature sending unit (located on the thermostat housing)
Per the service manual, use a high quality ethylene glycol coolant, mixed 50/50 with soft tap water or distilled water if soft tap water is not available.
For trackday usage you may need to flush out all of the coolant and replace with clean water with water wetter being the only allowed additive.