I have a 2003 700 sportsman and had some overheating/coolant disapearing issues this weekend that have me baffled and before i tear into it to check everything out i thought i would check hear first.. i have searched and found many overheating threads and coolant threads but nothing quite like mine.. so hear i go.. I went riding with my son 2 weeks back and got stuck in short ditch face first.. winched out..rode a little more than put it away.. This weekend we went riding again and i noticed my temp gauge was flashing.. we quickly rode back to my dads and started washing some of the mud off the front ( i dont think there is much if any on the radiator while it was muddy in the ditch i was not that deep i was just hung up) any way while i was washing it i noticed that the coolant was low so i added some let it sit for 5 minutes and everything seemed fine.. went for a quick ride to get it hot and had no problems... went back out with my son and halfway through the gauge flashed a few times and then quit. went back added some more coolant and everthing seemed good. came back 4 hrs later and the coolant in the bottle was gone but there was no water on the floor that i could see.. since that time i have filled the resevoir 3 times and the water keeps diseapering.. usually when its off. i check the oil and it is clean. Any ideas or things to check for would be good... one last thing... i went riding for about 45 minutes today and everything went fine..

 

Did you check the back of the rad..This is where the mud ...dried mud builds up and plugs the rad fins(fan side) ..........If good you may have a air-lock in the cooling system and need to bleed off the air run the quad with the rad cap off and slowly let it come up to temp.......adding coolant as needed ......This might push out some air in the system...........If your loosing coolant you must be either burning it or it is leaking/steam..........loss...........Caper.

 

When your filling your rad have the bike running and up to temperature that way the thermostat is open allowing you to fill it . It also could have air in the system that your need to burp out . Is your fan working ?

 

Both times when i filled it up the the atv was on and running and the fan is working. When i would fill it up i would then run it and the water level would stay constant in the overflow and then after it was off it would dissapear. i am starting to think that it was just low. i am going to fill up the rad directly tonight and run with the cap loose and see what happens...

 

i had a water pump seal go bad on my 500 ,and it sounds like yours. it was leaking so little that i never could find out where the water was going untill it fully went out and then water was pouring out. check the weep hole for stains,right front lower side.

 

I had the oil seal and water pump seal go bad and you couldn't tell because the weep hole was plugged with mud. It eventually did show up on the oil dipstick but it seemed that a lot of coolant "disappeared" until I finally noticed the the fill tube was way over full and the oil looked milky......Also I was told by the dealer that you need to prime to line between the overflow tank and the radiator but focing compressed air in the hole on top the the overflow tank until the coolant fills the line. Wehn you remove the cap it unpressurises that line...according to the dealer.

 

Ok so forget most of what i said in the first post... except the part about the mud and the ditch... Heres what i have found out so far. So apparently i was a little deeper than i thought and the rad was completely plug up.. My question is how do i get it cleaned up. i am sure it will work fine (i have taken an air hose to it for about 1 hr and can see a alot of light through rad but while i have it off i would like to get it perfect so any suggestions on how to get the rest of the mud and seeds and weeds and etc out would be great... i am also wondering if it was clogged up how quickly would it get hot and start leaking out the cap because i think/hope this is where the coolant went and it was just really low. I also talk to my uncle who was a small engine mech for 20+ years and he said that i should fill the rad first and then fill the overflow.. my last question is how do i straiten the front of the frame right below and in front of the rad (its part of the shaft that you see alot of guys have there winch cable hooked too) because apperenly when i winched out i must have put a lot of force on it and it is just barely touching the rad. lastly if the rad is leaking(maybe jsut a little havent confirmed yet) is there anything i can put in it to stop the leak.

 

The best way to get the rad fully cleaned is to remove the front storage rack......................Caper................
Also remember the rads usually plug up in the back more behind the cooling fan shroud!!

 

There is an over the counter product and I think it is called quicksilver and it can be used as a temp patch for a leak. Ask you auto parts store counter person I am sure they can direct you. (this would not be a long term fix)
strap it to a tree and attach someone elses winch to the frame and pull
However the best answer would probably be go to a local shop and have them tie down the quad to the floor and use a come along to pull everything out. Figure 1/2 hour to tie down and 1/2 to pull or one hour total labor if is worse than described figure 2 hours at most.
Keep an eye on your exhaust if your ride heated up and the gasket went you will have white smoke , as someone mentioned earlier their oil was milky. That is the coolant working its way around the head gasket seal that warped due to overheating.
Good Luck

 

My problem was very similiar as well. The entire rad was clogged. I removed the rad and soaked it for hours in hot water and then used a soft bristle brush to remove the mud between the fins. Also trying to flush the dirt out, i spent hours just soaking, brushing, rinsing, soaking, etc. until most of the rad was clean. In my case when the rad overheated, it warped the filler neck just enought that it would leak a little out of the top even thought it looked and felt sealed. I ended up replacing the filler neck and put a new rad cap just be sure. The was in addition to the water and oil seals that I mentioned earlier.