2005 Polaris Sportsman 800 EFI Overheating

[auditorguy]

Hello everyone, a new member with my first ATV, a 2005 sportsman 800 EFI.  I got a good price on it because it had no brakes.  A new hand brake, cylinder for the rear brake, rebuild the front calipers and replace the rear has them working.  The machine runs great but overheats.  I hosed out the radiator and found a leak on the water pump, new gasket for that is on order as is a thermostat and sensor,  As long as I had to drain the system I figure I should do the thermostat and I think the sensor is the problem since the fan works fine if I put power to it directly and it doesn't seem to be starting until after the machine is hot.

Anything else I should be checking?  Any suggestions appreciated.

[Admin]

@auditorguy I split your post out of the topic you posted into and started a new topic for you since its related to a different topic than the topic you replied to. 🙂

[auditorguy]

Thank you!

[BRoth82]

I know when I had my 2005 700 EFI, if it was using it for a long time in low gear pulling a yard drag it would over heat there was not enough air flow through the radiator to effectively cool it down .  I found on mine that the engine gets so hot that it would vapor lock the gas tank.  You could hear the gas boiling.  If you let it cool down it would run great again, I know a lot of guys were switching to a carisle fuel pump to and had a lot of success with that.  The exhaust pipe gets very hot also so i ended up wrapping it in header heat wrap all the way from the exhaust manifold to the tail pipe.

[auditorguy]

Thanks, I will keep that in mind if I am working it hard, I do plan to pull a good sized trailer with it.  But for now, with the new Thermostat and sensor the fan kicks in nicely and seems to be cooling fine.  Just to be extra sure the radiator fins were clean I used cleaner made for air conditioner exchange units and it did get out some more dirt, the radiator looks like new now.

 

[BRoth82]

It sounds like you fixed it awesome.  One thing to keep an eye on is if your right leg is getting really warm from the exhaust, the heat wrap really makes a huge difference.  Before I put it on if I was wearing shorts my leg would get red, after you couldn't feel any heat.  It's awesome stuff and really quite cheap.

[auditorguy]

Thanks, when I am towing I will check for heat on the right side and if I feel it heating up I will head for the heat wrap first thing.

[BRoth82]

Just ask if you need any other help, when I had mine I ended up replacing the Tbap wire harness, the hall effect speed sensor, cleaning the fuel sender unit, CV axles handle bars and a couple of other items.  One trick I did learn if you're replacing axles is to use a wood chisel to get between the axle hub and the differential housing it will pop the axle right out.  Those axles have a snap ring you need to collapse in order to remove them, the wood chisel trick saved me a ton of time. 

[auditorguy]

@BRoth82 Thanks for the offer of help but I am kind of hopeful to spend more time riding than working on the machine.  New brakes and cooling system work done, now I want to ride.  But since you offer, how do you set the idle?  It starts great but the idle is too low and it stalls after a minute or two even when the machine is nice and warm.

 

[BRoth82]

Great question, I'm not sure I never had to mess with the idle adjustment on mine.  Hope someone else can chime in that has a service manual or has done it before.