did you check the radiators to make sure they were not blocked with mud front and back??

 

no i have not checked for that but will.
Thanks

 

Like stendori mentioned dirty radiators were a problem on many machines,even more so on the big twins that could over heat fast.Later models the radiators were raised up a little and angled to help on this. Plus one being 9 years old,the other 13 years old,I can imagine all the dirt and caked on mud trapped behind the fan shroud from over the years. I'd clean both first,bleed the systems and go from there. Could be a stuck thermostat in one or the other,but best to start out at least with a clean system.

 

Thanks OPT. I will take the rad out tonight and give both real good cleans. While i have the system apart is there a way i can check the thermostats? And where are they located? Sorry new to Quads and don't really know where to start.

 

When you drain and pull the radiators you can check the thermostats. Both are on the side of the engine. Should open in a cup of boiling water. The t-stat o-ring is also the housing seal and can be reused if not damaged.If you need to replace one,ebay or amazon has them for around 25 bucks. If you need manuals on these new to you machines,you can get a pdf service manual for 5 bucks.Polaris ATV Service Manuals PDF Download

 

I had a 2007 Polaris Sportsman 800 X2 deluxe for two years. It spent 3 months in the shop at various times due to overheating. They could never figure it out. They changed the radiator 2x and the thermostat 2x. All this started after getting muddy water on the radiator. Hope you have better luck.

 

Temp sensors on the early ones were a problem on random 800 machines also. Had to install a 33 ohm resistor inline on the sensor harness on a few to help sync the sensor to fan activation. Recommended by a Polaris engineer and this seemed to help on the ones that got hot before the fans were able to kick on. I tried everything before and couldn't find the problem or fault.That may be what happened to your X2? This is basically the same thing I posted about in 2013 for another members 800.Never head back from him though.

 

I have read through this whole thread and seems very helpful and gave me some things to check. Here is the problem/symptoms I am having with me 2008 Sportsman 500 HO carbureted, It was bought as a project toy and I have done a lot of work on it getting it up and running. I was having an issue with overheating and I have replaced the temp sensor, replaced the thermostat, flushed and cleaned the radiator, tested the fan (hooking directly to 12 volts) it works but will not kick on when the HOT light comes on. After exhausting every option I could think of, I ended up just wiring a switch to the fan and just turning it on when I would ride. I would have just turned it on and off when the HOT light came on but the temp sensor had a loose wire and the light would stay on. Eventually running the fan from the switch was causing issues with the draining the (Brand New Lithium) Battery. In my research I've seen mention of the fan relay but have not been able to locate one on my quad. I am also starting to wonder if the issue could potentially be in the PDM which could also explain why the battery doesn't seem to stay charged when running the fan. Any thoughts or advice is greatly appreciated! Thanks.

 

Talk about bringing a thread back from the dead, lol.

There is NO way a stock machine will keep your battery charged with the fan constantly running. I forget the exact numbers, but the stock voltage regulator only puts out about 42 amps AT around 3000 rpm. It only puts out around 25 amps at idle. The fans on these things pull a huge amount of current, and it's almost impossible to keep the battery charged when the kicks on while you're riding, let alone while idling. Add anything else (like headlights), and it'll barely give your battery more than a trickle charge even while riding. A possible solution for you would be to buy a 65amp RZR 800 voltage regulator from CycleWorx. The RZR 800 has the same VR as the Sportsmans of those years. They're pricey, but well worth it. I have one on both my 08 RZR 800 and 08 Sportsman 800.

As for the overheating, my first 2 guesses would be air in the system, and/or clogged radiator. I see you cleaned your radiator, but there's no mention if you properly burped the coolant system afterwards. If you're positive the system was properly burped, and based on what you say you've already replaced and tested, my next guess would be possibly worn rings causing compression blow-by. But for right now, I would make sure the system is completely burped before moving forward. It doesn't take much air in the system to cause overheating. If you want a service manual for your machine, give me your email, and I can give you a link to download it from my one-drive.