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1990 Polaris Indy 500 - Overheating

4371 Views 7 Replies 6 Participants Last post by  SledHead
ok, a little history. I ( with lots of help ) replaced the rings, but did not do the pistons. Sled ran fine for about 200 miles and then overheated. The coolant was very foamy. SO here is what we did: checked the oil pump, primed it, checked the water pump, bled the coolant, synched the carbs and tuned the air flow ( found some one with the tool ). It ran for about an hr and did not overheat. I am not sure the problrem is fixed any thoughts? I have one person who said I should have replaced the pistons? any thoughts/suggestions?
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we also adjusted the choke. The sled was hard starting, which is never did before. it always started easily, so I am not sure if this was related. After all the work we did it did start easier.
Run it till it pops! j/k No, seriously if you did everything you said you did, and did it right, I would think its all set. You said you ran it for an hr or so w/no problems right? My only suggestion would be to monitor the plug color for a while at least. Check it every 25 miles up to 100 miles. If you continue to see a nice cardboard color on the plugs, and it doesn't over heat anymore, you should be all set. Best of luck to you.

1997 XLT SP 600
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I have to add something. Is this a liquid cooled machine. Just a key thing, snow has to be moving onto the cooling fins under your sled (im not sure of the exact name of them), if not enough snow is moving and they are not cooling the coolant then you will overheat. Make sure all the hoses running from each one are good with no cracks and/or holes.

If it is fan cooled then disregard the above statements, but since you said it had coolant I presume its liquid.

obviously this is liquid cooled, since gm mentioned the coolant was all foamy, you must have overlooked that.....but anyways i hope everything works out, but also yes, if not enough snow is comming in contact with your 'HEAT EXCHANGERS' then it is possible this is why you would be overheating, or maybe you had an air pocket in the cooling system someplace,,, just my thoughts.

1993 xlt sp 580
xtra 10 suspension
Heres my take on the situation, #1 Make sure you have completely bled the cooling system. you need to elevate the front of the sled when doing this and run the engine at a very low rpm. And it sounds like you did just fine when you rebuilt your engine. If the pistons were not scored then there was no need to replace them. As was said in another post, keep an eye on spark plug color.

Now i have to disagree with everyone when they say you need snow on your "heat exchangers" to keep from over heating. Granted the engine will run very hot, but it should not turn on the idiot light. I installed a Temp Gauge on my Triumph this past year, and i was very surprised to find out that without snow on the exchangers, it runs right on the edge of overheating all day long without overheating. Sure snow will help keep it running cooler but i dont think it is necessary to keep it in operating temp. If your idiot light is coming on, and you are sure you have ALL of the air pockets out of your system try a new temp sending unit or install a temp. gauge.

Just my two cents, take it for what its worth.

Polaris is my way out - Other people just use a door.
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Just one additional comment about the overheating. Last weekend I was crossing a lake that was glare ice. Because of this I was riding very slow to prevent melting my hyfaxes to my track. In this process of going so slow, and the fact no snow was coming in contact w/my heat exchangers, my temp light did come on. It was because of the slow speed I was driving at. I simply stopped for 15 min or so, then continued on w/no problems.

So I guess my point is that overheating can not only be caused by the conditions you ride in, but also HOW your riding the sled. And like Triumph stated, make sure there are no more air pockets in your cooling sys.

1997 XLT SP 600
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Now i know this is probly the stupidest thing ever said...but I'm brave, and will say it anyway. My 2 buddy just bought new 2002 mxz's (both identical) and we were just taking it easy, doing about 35 km/h and there idiot lights came on at the same time. we stopped for a min, noticed all the vents were closed, and oped them. We continued on and they were of 2 min later.

I know it sounds stupid...but it happends.
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