i have a big problem with overheating at high speeds has done this since new, have heard rumors of an aftermarket fix for this problem, i clean the radiator fins all the time with little results. anyone else have this problem?

 

If your rad is clean and the fan comes and works like it should and the coolant level is ok and bleed of air and the Rad cap holds its correct pressure,there would be no way for the engine to over heat.

 

although it's unlikely, it is possible for you to have a bad thermostat.it may not be opening up as it should.i'd try a flush &fill and have the radiator cap pressure tested and see what happens after that.

 

been flushed, no air pockets, fan works fine,only gets hot after running over an hour and being ridden at high speeds so it's not the thermostat because it would get hot right away. i have talked to several other polaris owners 500 to 700cc that have the same problem,I talked to one person who told me his friend fixed his with some aftermarket air deflectors can"t find this kit, can"t get ahold of this person.

 

All I can think of is from this site
4×4 Mechanic Confidential! | Transworld Quad

 

have already installed ford long life coolant with water wetter.i agree the big problem is dirty fins and radiator placement have considered mounting heater core to increase cooling capacity but no rooom , have also considered blocking front of radiatorwith plate a couple of inches away to create a low pressure area and reverseing the direction of the fan rotation,but i'm sure there is a less drastic answer

 

Honestly I never had a over heating problem with the 500 with our 97 or my 01 when everything is working right, my friend has a 01 500 Scrambler with a winch in front of his rad and yet it never over heats,but I ride in Northern Ontario Canada not in Hot climate.

Polaris must of recognized a problem though,because my 500 uses a 9" Fan and the newer ones have larger 11" fan now.

 

Some what true---If it gets hot real fast I would be looking at the water pump impeller could be slipping on the shaft or broke off. Check water pump pressure this will tell you the story. Air Fuel Ratio or being to lean,timing,plugged internal radiator,thermostat,incorrect reading from gauge list goes on.

 

only happens after riding over an hour and then extended high speed driving, not running lean will do with choke on,has done this since new so I doubt its radiator pluged inside, & it's been flushed.

 

Do you have spell check? Didn't get all of that Sir.