The Tusk Universal Digital Radiator Fan Kit is a great way to keep your bike cool when the trail gets rough. The heat sensor fits into the fins on your radiator so there is no cutting into radiator hoses.
I ordered this for a bike that already has a factory fan, but it would over heat on hot days and the factory fan turns on at 205 degrees F. I wired this kit up to my existing fan (factory fan is 8") and have it set at 185 F. Bike runs a lot better and it's not over heating on slow hot trails.