I have a 2002 Sportsman 700 twin. Just got it and thankfully the Ducati made ignition and stator have been replaced. I topped up the coolant and went for the first decent ride yesterday on the lake. Within 40 minutes it was overheating and boiled most of the coolant in the bike (-15 degrees celsius). And the fan is running fine. Not sure whether it has a thermostat or sensor issue, I'm hoping someone who has had a similar issue can help. Also, when the lights are on (high or low beam) as soon as the bike gets warm it will backfire and stall, however if I turn the light off it runs perfect...? Perhaps wires under the pod are rubbing or arching. Any ideas?

 

If the fan does cycle on and off the fan sensor in the radiator should be okay.Make sure the radiator is clean front and back especially around the fan area. This cause a lot of over heating problems on all atvs. Plus possibly you have trapped air in the cooling system also. Jack the front end up with the tires 6-8" off the ground,leave the radiator cap off and let the fan cycle on and off about 3 times. Add coolant when the level in the radiator drops.These models do take a little time to purge all the trapped air because of the way the hoses are routed. (Thermostats usually are not a problem unless it's gotten super hot enough to distort the seal or damage the small pin in the thermostat body) This should remove any trapped air pockets, then you can top off the radiator and coolant bottle. As far as the electrical it could be a short under the pod(where all the twisting on the harness mainly is) or a problem in the left switch or connections,but check under the pod first. Also check that you're charging around 14 volts at the battery while idling. Even though you have the new ignition kit and regulator,the previous owner may not have hooked the jumper wires correctly on the regulator.Even something simple as a battery not holding a charge may have something to do when it gets warm and dies. If it's the battery that came with it have it load tested.

 

You would be surprised how plugged the radiator can be unless you really look at. My overheat issues that occurred when the fan was running have always been a partially clogged radiator. Also to add to OPT is that I squeeze the upper radiator hose when it is running and the cap is off as and it seems to help "burp" some of the air out. i usually let the machine heat up and cool 2 or 3 times before I put the cap on and call it good.

 

Thanks guys, I will give that a try. Now however, when I turn the bike on and let it run for 10 minutes the speedo flashes indicating the bike is overheating but the fan is not engaging.. Maybe a problem with the fan sensor, or a fuse? I am getting the 14 volts at idle too so the headlight issue is making me wonder if I'm having some electrical problems?

Thanks again for the advice on the rad, it's cold as hell here but when it get's warm in a month or two I will spray down the rad as well.

 

There's a sealed fan circuit breaker under the front panel. Make sure you have 12 volts from each side. If not split the plastic pouch and check if the breaker is corroded. If the breaker is good,you can try 12 volts direct to the fan motor and see if it runs ok. If it does,then it's probably the #4010161 radiator sensor. Dirt Cheap Yamaha, Honda, Arctic Cat & Polaris OEM Parts & Accessories – Cycle Parts Warehouse Item #2 is the fan breaker.

 

That's great, thanks I'll give it a try.

 

My fan failure has always been the thermal sensor. To check it you can unplug the connector harness near the top of the radiator and where the prongs go, use a small piece of wire to "jump" the 2 areas and if the fan kicks on, you know the sensor is bad. I have replaced my sensor twice....Easy replacement.... part is about $50 online. I am assuming the 2002 700 is the same as my 2003 600..

 

Hey guys, thanks for the help, turns out I hit a stick and split the rad... Next question, do you know where the fuse box is located on a 700 sportsman? Thx

 

You have two 20 amp circuit breakers in sealed pouches. One is close to the battery(the main circuit breaker for power to ignition,lights,etc,may be tucked up towards the rear fender) The other one is under the front panel and controls the fan motor.You can split these pouches open and check for corrosion on the small metal breakers. Most auto stores will have them if needed. Item(s) #2 on the harness. Dirt Cheap Yamaha, Honda, Arctic Cat & Polaris OEM Parts & Accessories – Cycle Parts Warehouse

 

found them. I think I'm going to order the rad and do it myself, looks like the hardest part of the job will be getting to it. We did bypass the rad sensor yesterday before finding the cracked rad so the fan works and now that we know the rad was cracked and therefore had no antifreeze in it I am hoping the sensor is fine. The coolant resevoir was full however and didn't draw any to the rad, is this b/c it works on a vacuum principle and because the rad is split it couldn't draw the coolant from the resevoir? I see that you have previously mentioned cyclepartswarehouse.com for the rad sensor and I did go there to look up the price on a rad. I'm now looking to see if there are any Canadian sites for oem parts, if anyone has any suggestions? Thanks