Losing coolant when hot

[Mr.Firestorm]

Hi,

Last week while I was stuck in traffic I realised that the bike was getting really hot between my legs. I checked the temp and it seemed ok. It was getting even hotter, I looked again at the temp and it said cold ???? I started wondering what was happening. A guy ina car beside me yeld at me telling me I was losing coolant. I immediatly turned the engine off, looked, I was loosing a hell lot of coolant from the overflow.

I finally had a chance to look at it yesterday and realized 2 things :
1st: when the engine is hot, the fan doesn't turn on
2nd: when I turn the throttle, the temp indicator jerks from cold to hot....like it doesn't know what the temp is.

I am sure that the temp gauge and the cooling fan are related. Since the gauge is not working properly, is it possible that the fan doesn't get the signal to turn on? I still wonder....even if the engine wasn't cooling down, why was I losing all that coolant ?

Do you guys have an idea ?

Thanks

[interceptor]

How old is your thermostat? I would change that first it is probably stuck in the closed position. That means the coolant stays in the engine and doesn't go in the rads. Was it going in the rads? Were the rads hot? Anyway, check that, and let me know if this is the problem