I have spent a fortune over the last year trying to solve the problem of my 2001 Polaris Sportsman 500 HO running hot. My local polaris dealership can't figure out why it's running hot. They initially said the coolant system needed to be "burped" to get the air bubbles out, but it still ran hot. I put a bigger fan on and wired it to run full time, still runs hot. I flushed out and cleaned the radiator, still ran hot. We discovered oil in the water and they said that's why it wouldn't cool properly. They pulled the head and checked the gasket, but all looked good. They sent it to the machine shop and they finally saw it was warped and repaired it, but it still runs hot. They keep saying it's fixed, I pick it up and it runs hot in 20 minutes. It will sit and idle for hours though and never get hot. They've checked the water pump and said it's fine. It gets so hot it's melted the hose from the radiator to the reservoir. It's melted the 90* plastic piece that connects the reservoir and hose. It's melted the neck that joins the radiator and hoses where the cap is. They've replaced the radiator cap beacuse it melted all the rubber inside of it.
What can be making it run hot? Please help.

 

wow, that is a problem cchild by the sounds. sounds like youve done everything but change the engine. how about the themostat, did you take it and try it.

 

Have you checked your carb, could be running lean making the motor hotter, just a thought

 

<div class="FTQUOTE"><begin quote>Originally posted by: jhouse225

They sent it to the machine shop and they finally saw it was warped and repaired it, but it still runs hot. They keep saying it's fixed, I pick it up and it runs hot in 20 minutes.

Who is "THEY"..............Also the engine may be warped again if it's ran HOT for any long period of time!!!!..........Also how do you know it was fixed in the first place??..........If it runs fine at idle(not hot)..............Then I would say your burning coolant when riding.................do you see white smoke??...........Are you loosing coolant??...........That's would be my guess!!!..........
Caper...................

 

Did you put your water pump back together right ? Read this guys experience.

Sportsman Running hot.

 

I was at the Polaris dealership at 7:30 am when they opened and stayed there until 12. The mechanic was on vacation for the Labor Day weekend, so the owner piddled with the 4 wheeler for hours. He kept getting interrupted by customers and I got mad and left. He thought maybe the radiator was bad. I tried to buy a new one but he didn't have any. I remembered a former mechanic from the Polaris shop who had opened his own place and thought I 'd try him. I had to do something because I had a guy coming to buy the 4 wheeler at 2:00. He said it was probably just air pockets in the coolant system. He dropped everything he was doing and put my bike in the shop. He checked a few things then put the back wheels on the lift and raised it at an angle. He took the radiator cap off and cranked it. He mashed the throttle several times and added coolant and let it run several minutes. We could tell the water pump was working correctly because you could see the water swirling. The key was all the bubbles that appeared every time he mashed the throttle. He would raise the lift a little more, rev it up, add coolant and let it run. He would use a laser temp gauge to check the temp of the radiator and the motor. We kept repeating that process until all the bubbles were gone and the temp of the radiator and motor were the same. The four wheeler has to be tilted to get the air out.
The guy came to pick it up and we rode about 40 minutes on the hunting club and it finally ran fine with no overheating! I made my sale. I knew it was something simple. Th mechanic said the warped head could have been part of the problem, but when they put the head back on the system evidently was not "burped" properly. He said it takes awhile and you have to have patience. The laser temp gauge was handy too. Maybe this will help someone else. He said it's not that big a deal on most brands, but any time you mess with the coolant system on a Polaris...you have to make sure you get the air out.
If you need a good mechanic in the Cullman, Alabama area, call Stacy at S & S cycles.

 

Great news!!............It's sold though........What is next on your shopping list?.........Caper.........

 

air bubbles are a pain for sure, but ive been lucky and never had to lift the wheeler to get the air out. glad it got straighten out for the sale.