I have a 2001 Polaris Sportsman 500that is overheating coming with coolant coming out of the overflow. I have checked the temperature sending unit by removing it, placing it in a panic of water and heating it. At 195 degrees F it shorts which completes the circuit to the fan turning it on. The circuit opens back up at about 165f. I reinstalled the sending unit and it overheats again after idling for about 10 minutes. The fan never kicks on and it does not feel hot to the touch where the sending unit screws into the radiator. The top Hose is hot. Next I replaced the thermostat and the overheating is still happening. I see no signs of water in the oil. Radiator is clean. You can see through the fins by holding a light to it and turning off lights so I do not believe it is clogged. Any help is greatly appreciated.