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01 Sportsman 400 Overheating

3K views 10 replies 3 participants last post by  jbronson1 
#1 ·
I am looking for some help as my sportsman 400 has recently started overheating. I installed a toggle switch and direct wired the fan as I had thought that may help fix the issue and I thought it was working but then started overheating again. I am looking for suggestions on what to try next? Should I test the thermostat or with the fan being direct wired will that make no difference? Thanks for any help.
 
#2 ·
Hey brother I'm in the same boat, i have a 2018 polaris 450 sportsman H.O and it just started over heating yesterday while setting up some new deer stands.......only have 112 miles on it......first thing they told me was to clean the radiator i did that and now i don't think the fan works.......im trying to figure it out to if i get mine going or come across some helpful info ill let you know.
 
#6 ·
I just want to make sure I'm clear. You're talking about the thermostat in the bottom right corner of the radiator, correct? I removed it today but was not sure how to test it as it does not have a valve or anything on it but is almost like a solid plug. I have attached a picture to show what it looks like.
 
#8 ·
What you have pictured is a thermal fan switch. Its a simple switch that turns the fan on at around 197 degrees and off at around 180. The thermostat is located on the left side of the engine cylinder inside a fitting for the coolant line that goes to the radiator. It opens at a around 180 degrees to allow coolant to flow to the radiator. Its number 3 in the diagram below part number 3084940.
Here's a link to a thermostat for your machine on ebay and a picture of its location.
https://www.ebay.com/itm/Thermostat...=1137972097551c370340a11649fe8a95dc10e5de362f
 

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#10 ·
Thanks Polman500. I am going to pull the thermo today and test it. Does the thermo switch (#4) play any part in activating the thermostat or does it only relay to turn the light on? This light does not come on right now when the engine overheats and if I dont need it I would rather not buy it but if it plays another part then I will order one.
 
#11 ·
Quick update. So I drained and removed the radiator today and completely cleaned it out. You could see through it very well when holding up to the sky I also bought a new radiator cap to eliminate that problem if it was an issue. I refilled with coolant and drove it about 5-10 minutes and it was spewing again! I'm down to the thermostat or the water pump. I did find a tiny little hole just below the radiator cap where the overflow resevoir hose hooks up whether it just opened today, I dont know. Not sure if this would cause an issue or not
 
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