I just purchased a 1999 Sportsman 500 and am having a problem with the coolant leaking out very quickly. It appears to be coming out of the radiator cap under the front cowl or somewhere close by. I can't see where it is coming from, can anyone help. Also does anyone know where the thermostat is and if this could be the cause?
Any help would be great, I'm dying to ride, the mud is great right now.

 

Is there too much cooliant in the radiator? it might be overflowing

 

The coolant continues to leak until it is extremely low and then the overheating light comes on. It would appear as though I am losing all of the coolant. Thanks to anyone who can help.

 

How long does it take before coolant flows out?

 

maybe your cover is bad,or loose?or the over flow hose it broke at the radiator?where abouts do you ride in keene?i know most of the snowmobile trails but cant get to most of them seeing we cant run the old railroad bed..

 

About 10-15 minutes and then out it comes. I can only ride for about 5 minutes at a time after that and then it overheats and it's freezing here. I can't see where the leak is coming from directly????

 

This Diagram shows your thermostat and This diagram is of your cooling system

 

Could be lots of things, cracked radiator,blown head gasket,weak pressure cap, faulty thermostat, faulty water pump..

 

The cap isn't loose but I thought that it may not be holding adequate pressure either. Where would you start to diagnose the problem? I have worked on cars and motorcycles quite a bit but am new to the ATV world.

 

id start by taking all the plastic off,so you can get a good look.then fill the system up and ljust let the machine run,then just watch for it..hope ya get it fixed..