I have a 2000 sportsman 500. It began overheating and antifreeze began backing out of the reservoir and the cooling fan wouldnt come on. These symptoms sounded like the thermostat was sticking on it so we replaced it along with the fan sending unit. It ran great and had no problems. It sat for two months and now its doing the same thing. Does the thermostat just stick because it is siting so long durring winter or is there something else wrong. Or something were not doing right? Anything would be helpful.

Nate

 

Try leaving the radiator cap off until the fan comes on,could have air in system,then top off coolant and replace cap (air in lines can do this) If fan is kicking on and still over heating,check that radiator is clean and no mud packed in it especially at the back. (plus battery has to have a good charge for electrical systems to work properly such as the fan motor) OPT

 

if the fan is coming on and still is overheating and the radiator is clean front and back i would guess as mentioned you have air in the system some where. run the bike w/the cap loose after you fill up the sytem to where there suppose to be and let it set and idle w/ the cap loose to purg the air out. make sure you know the fan is working or it will over heat just sitting there so keep an eye on it. imo

 

crap i also forgot to tell you guys that the lights stoped working and the four wheel drive doesnt engage also. Could this be a control module out or something? all these problem occured at the same time. Sorry for forgetting that guys.

 

did the battery go dead or stop charging? if your battery is bad and you turn the lights on it will blow the bulbs, awd needs good battery too

 

the battery did die but after putting a new one in it ran fine and kept charging the battery. Ive worked tons on small engines and a moderate time on trucks and im simply stumped.

 

if it was run with a dead battery the lights usually burn out, have u checked to see if its circulating coolant into the motor at all, could be a water pump

 

Finaly got a chance to get out and crank it..It cranked just fine the battery is good and has plenty pf juice. The lights work, AWD still doesnt engage, and it started getting hot so i shut it down before it started overheating. First time this happened we replaced the thermostat and battery and it ran great. It sat for awhile and now the AWD doesnt engage and its overheating again. So could i have just gotton a bad thermostat or if they sit more than a month they stick. Also when i changed the thermostat i chaned the fluid so theres no water and i wouldnt thing there air in the lines because it didnt do it before. But ill run it again tomorrow with the cap off see if that changes anything.

 

If you changed the t/stat and drained coolant and just filled back up and replaced cap,you can have trapped air,Ive seen this dozens of times. As long as fan kicks in and cap off, air will be dispelled. Hope this solves the over heating problem. On the awd,have you checked/changed the fluid in the hubs, sure has power to hubs,can check connections under the front panel(small connectors with gray and brown wires OR just jack up front and back of machine and see if all tires turn in awd mode?

 

ill get out and check it all out today and let you all know what i find..thanks for helping guys yall are awesome