A friend of mine was riding his scrambler sat. and it started running bad and the temperature light would come on and he would have to stop for a short while to cool it off. The fan never came on so we figured it really wasn't that hot because the fan worked the day before. Then he was riding along pretty fast and it started running worse than it had before untill we heard a loud pop and a huge cloud of white smoke surrounded him. It ran better as soon as it "popped," but not there is a hole in the coolant reserve tank that you could stick your finger in. What could have caused this???? We have no ideas........

 

I've seen fans work intermittently. If your temp light is coming on, believe it, that means it's hot. I'm not sure if the newer design fans will fit, but maybe try to retro one in....that is provided it's an older unit. Also, whenever you wash your machine, backflush the radiator. Don't do this with a pressure washer, or you'll fold over your fins. Also, after flushing water through the fins, I sometimes take a blow nozzle with an extension and blow out the radiator from the rear. Now use some common sense here, hold the nozzle away from the radiator, or you'll fold over the fins with it also.

 

Sounds like a head gasket leak into the coolant, I had the same problem, only mine didnt blow a hole in the tank. Just would pour out of the resivor, and overheat.

 

when the red light temp turn on,it is hotter than it can be and already too late...shut the engine and stop to work the fans or cooling down the
the radiator,but a hole in the coolant system will do that for sure....