kabota atv500 overheating

[dmd170]

We have 3 kabota atv 500 and we do highway maint.we use the 500 for 10 hour a day picking litter some times it may be 10+ miles back to truck at the end off the day thay over heat on the way back . (Note we do run them hard) is there an atv that can handle this treatment with out over heating

 

[ohio farmer04]

Clean wash little door side screen is dirty
Check all oil

 

[ohio farmer04]

Check air fillter

 

[GolfAddict]

I've run our RTV500 hard plenty of times. I've had it start over heating twice.

In one case I had let the radiator fins get pretty clogged. I had cleaned the little screen in front pretty regular, but didn't realize the radiator itself had been getting build up over time. This is what I'd bet may be happening on yours. I check that every so often now.

I did have one other time when it started over heating, and I hadn't been running it very long, although pulling a heavy load. I cleaned the screen and radiator, but thought they didn't really look too bad. Started using it again and it started heating right up again.

I let it cool a little and popped the radiator cap. Fluid looked pretty good, but maybe a bit low, so poured a little mix in. As I was capping it up, I heard a sharp snap noise, and just knew the thermostat had just opened. Sure enough, no more problem. I've never had that happen other than that one time.

 

[dmd170]

Clean wash little door side screen is dirty
Check all oil

Clean rad and fluids cheaked dayly there run hard

 

[SpudHauler]

You didn't say if all 3 overheat or is it just 1 of them.

Flashlight shining through the radiator from one side and someone looking on the other, check the whole radiator for dirt this way. Light should shine through or be blocked showing you where to clean. Be careful as radiators are easily damaged.

Low fluid levels, when machine is cold in the morning the rad cap can be removed and it should be full as well as some fluid in the catch tank. If you've been using water to top them up, this is not as good as anti-freeze. Drain system and replace with 50/50 mix of water and anti-freeze.

I would re-torque the head bolts just to see if it helps. Can't hurt.

But most likely suspect could be thermostats. Try to find ones that are a lower temperature setting or at least replace with new ones.

Last thought, jack machine up and make sure the brakes are not dragging or stuck on. Wheels should turn freely with a little effort but not much effort.

Good luck.

Let us know what you find.

Unless the weather is extremely hot they should be able to handle this type of work.

 

[dmd170]

Ya , all 3 and one mule its not as bad. hot weather fla weather.high humity. rad are cleaned dayly we had that problem its only when there on the way back to truck at the end of the day runing wide open for about 5 miles they will start heating up . They do good all day till then

You didn't say if all 3 overheat or is it just 1 of them.

Flashlight shining through the radiator from one side and someone looking on the other, check the whole radiator for dirt this way. Light should shine through or be blocked showing you where to clean. Be careful as radiators are easily damaged.

Low fluid levels, when machine is cold in the morning the rad cap can be removed and it should be full as well as some fluid in the catch tank. If you've been using water to top them up, this is not as good as anti-freeze. Drain system and replace with 50/50 mix of water and anti-freeze.

I would re-torque the head bolts just to see if it helps. Can't hurt.

But most likely suspect could be thermostats. Try to find ones that are a lower temperature setting or at least replace with new ones.

Last thought, jack machine up and make sure the brakes are not dragging or stuck on. Wheels should turn freely with a little effort but not much effort.

Good luck.

Let us know what you find.

Unless the weather is extremely hot they should be able to handle this type of work.

 

[dmd170]

Thay are good machines, i think the cooling system is to small and were they put the rad there not enouf air flo . You have to remiber these mach Runs all day normal speed 8 to 9 hour maybe off for haft hour for lunch and a long way from there trucks there ready to go home . Need to modify the cooling system. were looking to buy two more at the end of the year but if we can't keep them cooled down need to find a diffrent one. Are mule is an 05 has done good till this year its getting wore out. the kabota 500 , one is two years two is 6 mouth just blowed head gasket on one last week.(it would help if the guys know what a temp gage was ha ha)

 

[Code54]

After you get everything cleaned out could you add an electric fan (put it on a switch) to add additional cooling if needed?

 

[texasjohn]

My 1140 has overheated for two reasons only.

radiator fins/screens are filled with dust/crud/grass bits....clean with water hose to clean out, air does not do it for me.

The attachment bolts for the electric fan melted the fan shroud plastic, fan detached and could not turn. I obtained a different fan/shroud and hooked it up again.

Your problem seems to be consistent across 3 well maintained vehicles and occur only under prolonged high speed travel at end of day when temperature is max, radiator has max dust and debris.

I can only suggest two things..

Clean the radiator screen of grass/debris before return trip.
Find if possible, a fan/shroud combination which will move more air than the factory version and use it instead. Might see if a larger radiator could be installed.

Oh, yes, final idea. I once had a car with huge mileage on it....radiator got increasingly clogged with minerals over time....symptom would be heating at high speed and high outside temperature. It slowly got increasingly worse. Replaced the radiator and problem completely vanished.
Perhaps your radiator would benefit from a pressure clean... or replacement if problem persists,.

 

[dmd170]

After you get everything cleaned out could you add an electric fan (put it on a switch) to add additional cooling if needed?

Ya thats my next move

 

[Code54]

I run two Kubota tractors and they are pretty decent at not getting clogged but even unclogged I am amazed at the amount of dirt I can rinse out of the radiator even when it looks clean. I personally found that if I spray the rad and let it soak for a few minutes before flushing it I can get the dirt out much easier.

As others have said check the thermostat as it can easily cause your issues.

Good luck!

 

[SpudHauler]

Four thoughts;

1 - how clean are the engine and transmission. Extra layers of mud and dirt on these aluminum engines act like a winter coat to hold heat. A good overall cleaning in the engine compartment might make a big difference.

2 - radiator fluid. Motocross bikes like a CFR450 Honda have small rads, due to weight of the rad and the coolant all add to weight which is important to racing, so cooling is always a problem given the mud and conditions they are used in. So one of the solutions is to use a special rad coolant that works better than the regular stuff for transferring heat. Engine Ice is good, Motul is good Maxima coolanol is good. Check at a local motorcycle shop for ideas.

3 - fan switch. The wire that goes to the engine block from the fan is just a ground that makes contact when the temperature reaches a setting. Tap a wire off this ground, add a switch and run the other side of the switch to ground and you can now control the fan. It will still work on it's own, but will come on any time you have the switch on.

4 - throttle stop. Add a throttle stop so they can't get full throttle. Just a few miles an hour slower might make the difference.

5 - thermostat. Try removing this from one of the machines. Will take longer for the engine to completely warm up but in the conditions you are working in that doesn't look like an issue. More flow might be the ticket to cooler engines.

Just some thoughts.

Good Luck.

 

[Gary Fowler]

My RTV 900 will creep up into the edge of red if I run it WOT for a long time. I don't think the radiators have the capacity to cool properly when used in High range WOT for long distances. A mile or so it stays in the white but then it will start to creep up. I have not had it get really hot enough to have to shut down but it will linger at the edge of red, slow down a bit for a little distance and it goes back to white. Even at the red, it doesn't have the hot fluid smell of boiling antifreeze.