Hey guys, picked up a 500 Sportsman today that needs a little work. Talking to the guy on the phone, he said it would get hot once in a while "like 500 sportsmans do". I knew that wasnt correct but decided to go look anyway. The biggest issue is it was stuck in reverse which I have already figured out for the most part.

So anyway, I figured this thing might overheat when he was working it the way he talked, but after I had payed him, just from it idling, the temp light came on as i was backing it into the truck and I noticed some coolant on the ground.

When I got it home, I checked and it was pretty full on the coolant. I jacked the front end up and tried to add some but once I got a little bit in it it was pulsing coolant back out of the fill. The coolant that came out was hot since I had ran it a little bit, but the radiator was still cold. Seems like for some reason it wasnt flowing through the radiator.

So, where should I start? The machine has a few issues but the overheating is the biggest one. Im hoping its not a head gasket issue. It starts and runs excellent, just doesnt seem to be cooling properly. I think the fan isnt working either, but if the radiator isnt getting hot then I know that is not the problem Im currently dealing with. Is the bubbling normal? Their is no coolant in the oil or oil in the coolant that I can tell. Thanks for any help guys!

Eric

 

where is the bubbling? if its constantly bubbling with the rad cap off you might just have a bunch of air in the system

 

bad thermostat ,trapped air, some kind of obstruction ,try to flush the radiator with a hose .

 

Cold feeling radiators are a lot of times caused by fins blocked with dirt and mud. A lot of people overlook the area behind the radiator around the fan shroud. Good place for dirt and mud to collect. I'd flush front and back with a hose,remove the radiator if necessary to deep clean the back.Has to have good air flow or will over heat. Check under the water pump area at the weep hole to see if you're losing any coolant there. If this area is dry and after you're certain the radiator is clean and flushed,jack the front end up,fill with coolant,run with the cap off to remove any trapped air. You can squeeze the hoses to help with this. You should be able to see the coolant level drop and top it off as it runs. Fan should kick on before the hot light. If it doesn't could be a shorted out fan sensor on the radiator. You can always run 12 volts direct to the fan to see if it's ok. If fan motor is bad,Spal is the maker. Several places you can get them.http://www.the-fan-man.com/shop/-c-33.html https://webstore.spalusa.com/en-us/p...rcycleatv.aspx

 

Thanks everyone. Its going to be really cold here tomorrow and the next day, and my building is not big enough to work in with the door shut and its not insulated either, so it will probably have to wait a few days, but I will start off with that.

From what I can recall, the radiator was fairly clean but I will double check. They've done some fancy wiring on the fan so no telling what has happened there. I think thats likely why it doesnt work. Gonna jump it to 12v and check the fan then go from there.

The main thing that seemed concerning was the bubbling. It was kind of blowing coolant back up out of the fill neck when I took the cap off. Hoping its not pressurizing the system because of a more serious problem. Ill update as soon as I get a chance to mess with it.

 

You don't say which year model you have,but yes on some the hoses have a lot of crooks and bends leading to the fill neck. Takes a while on some to purge all trapped air. Anyone messing with the fan wiring is usually a sign they've bypassed the radiator sensor.

 

Sorry, I didn't realized I hadn't mentioned the year. It's a 99 according to what I was told but I haven't confirmed that. Remington model maybe? I don't know, but it's camo and has the EBS.

Yeah I always dread it when some "mechanic" has been messing with the wiring. Hopefully they haven't messed it up too bad. I'm going to hot wire the fan first and see if it functions. Then I'll start tracing the wiring.

 

Easy on this 99 model to check the fan operation. Just use needle nose pliers to ground each side of the radiator sensor spade connectors located at the top of the radiator and the fan should kick on. These sensors were bad on burning out because if coolant got below them they would short. Item#6.Dirt Cheap Yamaha, Polaris, Suzuki & Kawasaki OEM Parts & Accessories – Cycle Parts Warehouse Plus you can match these sensors up at most auto parts. One reason why they moved them to the bottom of radiators on later models.

 

Alrght, I have a little update.

I got it out and let it run a while a couple days ago. I jacked the front end up in the air and pulled the radiator cap off and started adding coolant. It was taking it slowly and finally got to where it seemed pretty full. I let it down and put the cap on and took it for a short run and then came back and parked and let it idle for a few more minutes when the hot light finally came on. The fan never kicked on, so I ran a hot wire to the hot for the fan and it kicked on and I let it run until the light went off.

While I was adding coolant, I could rev the engine slowly up to 3/4 throtte or so and it was fine. If I hit the throttle hard all of a sudden, it would shoot coolant out of the fill neck. Is that normal? Im hoping yes, but it also seems like it could be cylinder pressure. There is NEVER any white smoke that smells sweet or anything out the exhaust. Not even on initial start.

It did have some small traces of oil in the cooling system. The coolant looked good, it was just that there would be a real small oil film on top of the coolant in the fill neck at times. Its definitely not much at all, just dont know why its there.

The radiator cap im thinking could be bad. When I was driving it and would give it pretty heavy throttle, it would blow a little coolant out around the cap and you would see it steaming(it was pretty cold that day). Its either the cap, or pressurizing the cooling system enough to blow it out and im not sure which.

The radiator is getting warm all over and seems to be clean so I think its working properly. The coolant temp sensor is at the bottom right hand side of the radiator and the wires run straight up where someone has hacked them and spliced them Ive got to figure out the correct wiring for that and get the fan working hopefully.

If I can get the cooling system figured out, Ive got some other small things that need fixing, but over all its in decent shape.

 

You've got at least a 2000 model if the radiator sensor is at the bottom of the radiator. Normal for some to have a small film of oil at the top of the radiators. I've seen that over the years even on machines that were extremely well maintained. Part of this could be seeping a little oil past the metal head gasket over time that gets into the coolant. You still may have trapped air as some machines take awhile to get rid of it all. I've had to have machines up in the air for as long as 30-40 minutes and have had fans cycle on and off as much as 3 or 4 times or more to get rid of air while I'm slowly topping off the radiator in between gulps.If in doubt on the radiator cap any auto supply has the 13psi cap for a few bucks. I'd replace the sensor on the radiator so you won't have to wire the fan direct. A Wells SW526 sensor would work. All you have to do is cut your oem connector and reuse it.Wells Vehicle Electronics Cooling Fan Switch SW526: Advance Auto Parts Plus don't over look the fan circuit breaker in the sealed pouch under the front panel. It must have power through it as it supplies the hot lead to the fan. The radiator sensor completes the ground path to kick the fan on.