Any ideas my 800 sportsman over heats when sitting at idel have antifreeze In it should the next step be the thermostat fan runs and the temp Spenser is working thanks a head of time

 

Year model would help as there were some changes. But you should be able to pull the sensor connector on this model and the fan and hot light should come on.Getting hot at an idle could be mud/dirt packed behind the radiator which is a common problem.Make sure it's clean. The sensor could be bad ,just check resistance when cold,then when warm,resistance should drop plus check the fuses/fuse block and check the harness leading up from the fuse block,should be a circuit breaker either taped on top of the harness or in a sealed pouch. If it's terminals are corroded/shorted out, it blocks power to the fan relay which triggers the fan motor.Found several of these that corroded.You can get this breaker at any auto supply if needed.

 

The year is2005 it's 800 efi the rad is clear and the fan runs on derect current and through the senser so the fan works the way it should that's why I asked about the thermastat I have also herd it might be the timing thanks OPT.

 

Trapped air is another problem that can cause one to overheat before the fan cycles on. Just raise the front end,remove the cap and let it run for awhile to remove any possible trapped air. If this doesn't help,then you could have temp sensor that's getting weak. Electrical timing is controlled by the ecu module.Thermostats rarely are a problem,but you can pull the housing,check that the thermostat seal is ok along with the small pin.Had had one that got super hot and the pin was cocked at an angle not allowing it to open at the correct temperature. You can also place the thermostat in hot water and see if it opens. If it's ok,after you reinstall it you'll have to bleed any trapped air again.

 

Ok thought I got all the air out but will check that 1st what about bypassing the sending unit and run the fan all the time if that works dose that mean getting new temp unit thanks

 

Fan and hot light should come on when you pull the sensing unit connector. You can test cold resistance on the sending unit,should show around 2.5k ohms at 68 degrees,then hit it with a hair dryer for a few minutes. Resistance should begin to drop. Plus simple things like the 13psi radiator cap seeping air can cause problems. On this model if the fan doesn't come on when you pull the connector,you can always jump the fan connector to see if the fan works ok. Plus on average if a fan draws more than 7-8 amps for it to run,could be the fan itself is a problem.

 

make sure the rad is clean behind the shroud as well. both my 06 and 08 had over heating issues after mudding from not being able to clean it out. even a 25% plugged rad. will make it over heat as the twins run hot anyways. imo

 

Thanks will check the ohms on the sending unit and the cap thanks opt and stendori

 

Put the front end up on blocks and ran it low and behold it bubbles out air sucked down the coolant filled it back up and no overheating .thanks for the infoe learned a good lesson.

 

That's what a lot of people think along with radiators are clean.. Doesn't take much of either,air or dirt to cause overheating in the 800s. Glad it was a simple fix. I still think the thermostat housings on the Sportsman 800 should have had a bleed screw on them like on the Rangers,but Polaris only thought that the Ranger needed it because of the long hose run. Would make bleeding a whole lot simpler imo. Plus nothing stopping anyone from changing out to a Ranger 700/800 bleed screw cover or even adding a bleed screw in the blank opening of their stock covers.#4 http://www.cyclepartswarehouse.com/f...2006&fveh=7133