Guys I have a 2002 sportsman 700 carb model,, I have installed new cap,relocated radiator to top rack and bypassed fan sensor to toggle switch and run in on all the time until I plan on getting it wet,system is purged, problem is here ,,when I relocated radiator I clean rad good, I can let atv idle for hours and won't overheat or blow coolant, it gets to blowing coolant once I ride it hard for a lil bit with the fan constantly on,last time it blew out the top of over flow was last week when I was runnin against a friend on my 500 just to see how much quicker it was,, needless to say after a good run it was blowing rusty coolant water out of top of overflow resivoir as usual ,,, could it be the water pump impeller is not circulating enough water and need to check it ,, or I read systems is head gasket,, but it doesn't smoke or make any noises, it only does this when I get in the throttle real good,, please help any advice is appreciated!!

 

If it didn't overheat before you relocated the radiator then possibly you still have trapped air because of the added length of hoses and time it takes on some to really purge air. I'd still jack the machine up,leave the radiator cap off and see if it purges any more air from the system. Yes it's possible also that an impeller can wear down or partially melt from heat over time because of cavitation from air in the system or even if the impeller nut has simply backed off and not enough coolant is pushed through the engine and radiator. If you're going to pull the water pump cover be sure to have a new o ring for it. Also if mine and I was modding something like this,I'd just go to an aluminum impeller to be sure. http://www.ebay.com/itm/Polaris-Sportsman-600-700-800-Twin-Billet-Aluminum-Water-Pump-Impeller-5433684-/161672998791?hash=item25a4762f87&vxp=mtr

 

Overheating
• Low coolant level
• Air in cooling system
• Wrong type/mix of coolant
• Faulty pressure cap or system leaks
• Restricted system (mud or debris in radiator fins
causing restriction to air flow, passages blocked in
radiator, lines, pump, or water jacket, accident damage)
• Lean mixture (restricted jets, vents, fuel pump or fuel
valve)
• Fuel pump output weak
• Electrical malfunction
• Water pump failure/ Loose impeller
• Thermistor failure
• Cooling fan inoperative or turning too slowly (perform
current draw test)
• Ignition timing mis-adjusted
• Low oil level
• Spark plug incorrect heat range
• Faulty hot light circuit
• Thermostat stuck closed or not opening completely

 

Thanks for the I put guys, and yes it's been doing this for a while now, like I said I purged it and if your just cruising around no problem, but when you get on the throttle for a length of time it starts to blow out the top of overfill jug, it doesn't smoke or have any problems running at all, so do y'all think it cold be a simple fix as the impeller or maybe worst case a head gasket??

 

Plus does the fan cycle on and off before it starts spewing out the radiator? If not a radiator sensor may be the cause. Plus open the cap and see if you see coolant flowing around in the radiator. If it's a weak flow then could be the impeller or in rare cases a thermostat can be faulty. Had one that the pin caught side ways in the thermostat and wouldn't let it fully open. If it was a head gasket you'd normally see leaks or smell coolant burning through the exhaust or it would be smoking.

 

Thanks for the reply opt,, the fan is ran off a toggle switch that stays on unless wheeler goes deep in mud, but since all the mods hve been done to it last year ,it hsnt even seen the mud, so every time wheeler starts spraying from top of over flow jug is when I'm ridding full throttle down a dirt road with the fan continuously on, I hve the overflow jug mounted on side of radiator relocate kit on front rack of bike, wld that matter,placement of overflow jug?? And far as leaking water ,smoke, or smell of coolant is a no, I'm surely hopin it's a easy fix of impeller??? Thanks for all help or suggestions!!

 

You might try a different mounting spot for the overflow bottle and see if it helps. If it still spews out then I'd check the impeller and while you're at it pull the thermostat and check it in boiling water to see if it opens up.When it's back together you have to go through the air purging again.

 

ok sorry for the late replies guys, been busy at work and no time fool around with wheeler. so here I am today after a lil more work has done to it..so far I have replaced the mechanical seal , oil seal , and replaced the impeller wich was completely worn in wich cause the over heating issue that started this whole thing, after replacing all seals and clean out the dirt filled weep hole, I filled rad up with water today without starting the bike and let it sit there and fluid started dripping out of weep hole not fast but continuous drip, do I need to start the bike for the spring on mechanical seal to set right? or shld it not drip at all to begin with, I read forums about the the shaft being bent and cases like that but when I took bike apart I didn't see none of obvious , any ideas wld be greatful , thanks

 

Shouldn't be dripping.. Did you take the outer case off to replace the seals away from the engine or did you pry the old ones out with the case intact? If you did,then possible you bent the shaft.

 

I took it completely apart!!