[Mustangnut6788]

Ok I have a 1996 Arctic Cat ZRT800. I am having some cooling issues with this sled. If anyone can add any advice I would appreciate it. I want to go north to michigan next weekend but I don't want to drive 4hrs to have it crap out on me AGAIN! Arghh!

The original problem was that the sled kept over heating and boiling over into the overflow tank. Niether exchangers were getting hot. This yeilds me to believe that I have a cirrculation issue. Although I had flow while flushing the front exhanger does have some impact from studs, which I am keeping in the back of my mind.

Things I have done to try to fix it:

• Flushed out all the lines and motor with garden hose, appeared to be no blockages
• Rebuilt the waterpump with a new spring seal
• New thermostat
• Purged all the air out, elevating the front of the sled
• I checked coolant mixture and it was ok

Ok after all that I started it up and it was cirrculating as the exchangers were warm. The next day I went out and started it up and there was no cirrculation. Exchangers were not getting hot, it built pressure and eventually the warning light came on.

Please tell me whats going on. This thing is driving me bonkers. bang your head I dont know what else to do.

I'm sending out an SOS!

 

[A G]

At first I thought the thermostat might be getting stuck closed.

But that doesn't make sense if you see the coolant coming out of the heads into the reservoir.

Have you checked the theromstat?

 

[Mustangnut6788]

Yes I put a new thermostat in..... I dunno

Thanks

 

[buckey14]

Put a posting out for snow800. Mike is his name he's in monroe Mi. knows his stuff when it comes to Cats, he's helped me many times. Dan.

 

[slick]

Hello. was going through my manual and looking for issues. The clear line that goes from the bottom of the coolant tank to the lower coolant line has a special check valve in it that removes the air from the system. maybe its malfunctioning and the coolant is getting past it and up into the tank. Other than that, thermostat or maybe the pump isn't turning.

 

[Mustangnut6788]

Well I have checked the valve and it seemed to work. As for the pump, did I miss an important part in rebuilding it? I put in a new spring seal, bolt, and washer. I also put loc-tite on the bolt to keep it from coming loose.

slick,
On your diagram there it shows that 95's require special non pressurized cap. Do you think its possible that someone replaced it with the wrong kind and this is giving me troubles?

 

[slick]

That very well could be a possibility. If it pressured up it could have damaged the check valve. That check valve should only let air through, not liquid.

 

[Mustangnut6788]

Well when I had problems with the overflow tank it was coming from the cap not the valve, I think. I am not having that problem anymore, now I just cannot get any cirrculation. Maybe I'll try elevating either end again and double check for air pockets. I was positive I got them the first time, ohh well its an easy thing to check.

 

[blackmax]

O-ring in one of the heads is gone or split... it will overheat and blow coolant out of the bottle... pull your pipes and see if there is coolant sitting by the exhaust port....


BM...

 

[Mustangnut6788]

Will it hurt anything if I pull the heads off and inspect the O-rings? Will it trash the head gasket? I had the pipes off when I rebuilt the waterpump and I do not recall seeing any. Its not pushing water into the overflow anymore its just not cirrculating.

Thanks

 

[onefasttact--off]

Did you try bleeding the coolant system again? It sounds like a air lock to me, it can happen & it will do whats happening to you, boil over with little or no curculation. Pop the cap off & lift the front of the sled again to rebleed it may have to let it sit for awhile, if the coolant goes down after some time then it had air. Give it a try, sometimes not all the air come's out on the first try. Wont cost you a thing to try!!! HTH

 

[blackmax]

how did the impeller look when you had it off?? wasnt rounded ( the groove for the shaft was good )??? or did you put a new one on... lift the sled front high and leave her sit over night... and refill... and if you decide to drain coolant again, I would pop the heads and put new o-rings in... for it to pressure up, it has to be a airlock or head gasket... did you try a new rad cap yet? not leaking where the stud marks are on the exchanger?? why not pull the stat out and see if you can get it to circulate and warm up in the garage... (if garage is heated) I dunno

BM....

 

[Mustangnut6788]

I reused the impeller as I saw no visual reason to discard it. I haven't tried anything yet and won't get a chance to until sunday. So I'll try purging more air out then. If it was a head gasket you would think that there would be limited flow because 2/3 of the cylinders would have flow, just one cylinder would be hotter than the others, but thats not the case. Its not leaking from the heat exchanger I was just wondering in the back of my mind if it collapsed some of the cores on it. As far as a heated garage goes yes I have one but I haven't needed to use the heater that much so far as it was 51 degrees out today! Dear god will it ever snow?

Thanks everyone for your help so far!

 

[onefasttact--off]

Hey blackmax I see your in Sask Rockerdude any chance your around Toon town? Were you in the storm?
Sorry to hijack just want to know... BTW I do think its just a air lock, a leaking head gasket will cause the same effect as blackmax allready stated. BTW blackmax do you have a clutch alinment tool I could borrow?

 

[snow800]

<div class='quotetop'>QUOTE (Mustangnut6788 @ Jan 12 2007, 05:06 PM) <{POST_SNAPBACK}></div>

Ok I have a 1996 Arctic Cat ZRT800. I am having some cooling issues with this sled. If anyone can add any advice I would appreciate it. I want to go north to michigan next weekend but I don't want to drive 4hrs to have it crap out on me AGAIN! Arghh!

The original problem was that the sled kept over heating and boiling over into the overflow tank. Niether exchangers were getting hot. This yeilds me to believe that I have a cirrculation issue. Although I had flow while flushing the front exhanger does have some impact from studs, which I am keeping in the back of my mind.

Things I have done to try to fix it:

• Flushed out all the lines and motor with garden hose, appeared to be no blockages
• Rebuilt the waterpump with a new spring seal
• New thermostat
• Purged all the air out, elevating the front of the sled
• I checked coolant mixture and it was ok

Ok after all that I started it up and it was cirrculating as the exchangers were warm. The next day I went out and started it up and there was no cirrculation. Exchangers were not getting hot, it built pressure and eventually the warning light came on.

Please tell me whats going on. This thing is driving me bonkers. bang your head I dont know what else to do.

I'm sending out an SOS![/b]

There are several things you can try,

First thing I do on the 95, 96 and 97 ZRT's is put a 1998 coolant tank on them, instead of just a 90 degree fitting with a cap in it, The tank holds a extra quart of coolant that aids in cooling. You just cut about a inch of of each hose and it will go right in.

Redline "Waterwetter"
I run this in all my big bores and it drops the operating coolant temp by 5 to 10%.

Change the track, The older ZRT's only run a .720 track, the paddles are not tall enough to "fling" snow
on the coolers, expecially the rear one.

Also the only reason that sled has a thermostat in it is to keep the warranty claims down on the cold seizures,
Take and cut the center out of the thermostat and use it as a "water reducer", this will not restrict the flow of coolant, making it run cooler. If it still runs hot, just put the rubber gasket that wraps around the thermostat in there without a thermostat.
It will "pinch" between the water neck and the housing and stay in place. I had to do this on a 1107 to keep it cool.

Just run it for at least 10 minutes and never go past 1/4 throttle before you hammer it.
That way you won't have a cold seizure.
Mike

 

[blackmax]

Take and cut the center out of the thermostat and use it as a "water reducer", this will not restrict the flow of coolant, making it run cooler


do you have a pic of a cut stat out... I would like to see what you are taking out :thumbsup:


BM...

 

[snow800]

You just cut the band that goes across the top and the one that goes across the bottom at the flat part of the stat.
I don't have a picture, but I photoshopped what it will look like before and after.

 

[blackmax]

I see... thanks... so just the stat ring is left and the spring and plunger is gone... cool mod :thumbsup:



BM...

 

[blackmax]

<div class='quotetop'>QUOTE (Mustangnut6788 @ Jan 13 2007, 12:31 AM) <{POST_SNAPBACK}></div>

I reused the impeller as I saw no visual reason to discard it. I haven't tried anything yet and won't get a chance to until sunday. So I'll try purging more air out then. If it was a head gasket you would think that there would be limited flow because 2/3 of the cylinders would have flow, just one cylinder would be hotter than the others, but thats not the case. Its not leaking from the heat exchanger I was just wondering in the back of my mind if it collapsed some of the cores on it. As far as a heated garage goes yes I have one but I haven't needed to use the heater that much so far as it was 51 degrees out today! Dear god will it ever snow?

Thanks everyone for your help so far![/b]

if you still dont have any sucsess with the airlock and stat suggestions, I would still concider your head gasket...when I had a bad o-ring on one, the sled would warm up idling and the exchangers would get warm... BUT after 5-10 minutes of driving hard with the rpm working hard, it would start to heat up and blow out... the o-ring was holding just enough at slow speeds until I started WOT blasts... sometimes I could drive 10 miles slow before I had any problems.... (trust me that is very hard to do on a TCAT.. lol)... just another option for ya....
how did this problem start ??? sled was working good before and then it justed to heat up and boil over or did you drain the coolant at one point and then the problems started ???

BM...

 

[bobd1950]

<div class='quotetop'>QUOTE (blackmax @ Jan 13 2007, 09:11 AM) <{POST_SNAPBACK}></div>

I see... thanks... so just the stat ring is left and the spring and plunger is gone... cool mod :thumbsup:



BM...[/b]

From what u describe...removing the thermosat..or putting a restictor in its place wont HEAL a faulty system. A 1970's fix,but its a good way to take about 50% life of the cyl. and use more fuel.,esp. w/ a carbed engine.
Can u say piston ring wash= no seal and blo by?


A small but important part of the cooling system is the thermostat. Its job is to get the engine warmed up as quickly as possible by restricting the flow of coolant until a preset temperature is reached.

Although it’s important to keep a 2 cycle engine from overheating, it is equally important to prevent over-cooling. Over-cooling encourages ECU rich fuel settings/ cold siezures/ the formation of acids and sludge in the oil. It also tends to reduce combustion-chamber temperatures by quenching the flame front. This results in higher emissions and greatly reduced fuel efficiency, because much of the fuel remains unburned. That’s why it is never a good idea to substitute a thermostat with a lower opening temperature than that of the one you are replacing.

After the thermostat opens, the coolant circulates between engine and radiator, maintaining a temperature between 115and 155 degrees F. It picks up a normal increase of 15 degrees as it passes through the water jacket surrounding the combustion chambers and cylinders.