How Vulnerable is a 02 800 XC to Overheating

[Johnsong]

I'm just getting back into snowmobiling after many years. I picked up an 02 Classic 550, very low miles, and it is great. Now I picked up an 02 800 XC with 1600 miles, thinking I got a good deal for $1300. Very clean and started/ran well. Took it out for maiden voyage. Went less than 2 miles and hot light came on so I stopped immediately. Turns out crank has burned bearings, thermostat was melted, and hi fax melted to the track, coolant level was good and pump was working. My mechanic is sure the unit had prior issues and I didn't cause damage.

I'm now having unit rebuilt, including ice scratchers and new hi fax. Basic question is how vulnerable is the sled to overheating on primarily groomed trails? Anything I need to watch so I'm not broke down on trail again?

Thanks for any insight and advice.

 

[rabbi]

First off, welcome to Polaris Star Power. You will find lots of good information here.
I hate to be the one to tell you this, but if the hyfax melted to the track, it overheated due to lack of snow which is what lubricates the track clips andhyfax. The snow also cools the heat exchangers. Without snow, it will overheat very quickly. The thermostat was wide open but the coolant got too hot. That probably cooked the engine.
What were the conditions when this happened? Was it early morning with iced over trails?
Ironically, your 550, being fan cooled, would been fine under the same conditions, other then smoking the hyfax.
Don't beat yourself up over this. It happens. In the future, scratchers will definitely help. In 2002, Polaris had a cooling system TSB which recommended a rear cooler in addition to the full length tunnel cooler. IIIRC that same TSB recommended a longer snow flap if the sled came with an M-10.
I had a 2002 800 XC, and never had any overheating issues. But I was always watching for low snow or iced up trail conditions.
I would also consider installing a coolant temp gauge. A lot of times, by the time the temp light comes on, it's too late.
If you're out riding and the sled seems to be holding back, like you're riding the brake, that is the first sign of the hyfax getting hot and sticking. dip off the trail immediately into loose snow and giver to throw snow up onto the track and coolers. Some guys say to pull over and shut the sled off, but at that point the sled is going to overheat even more due to lack of circulation. Best to get some much needed snow thrown up to cool it down.

 

[Johnsong]

First off, welcome to Polaris Star Power. You will find lots of good information here.
I hate to be the one to tell you this, but if the hyfax melted to the track, it overheated due to lack of snow which is what lubricates the track clips andhyfax. The snow also cools the heat exchangers. Without snow, it will overheat very quickly. The thermostat was wide open but the coolant got too hot. That probably cooked the engine.
What were the conditions when this happened? Was it early morning with iced over trails?
Ironically, your 550, being fan cooled, would been fine under the same conditions, other then smoking the hyfax.
Don't beat yourself up over this. It happens. In the future, scratchers will definitely help. In 2002, Polaris had a cooling system TSB which recommended a rear cooler in addition to the full length tunnel cooler. IIIRC that same TSB recommended a longer snow flap if the sled came with an M-10.
I had a 2002 800 XC, and never had any overheating issues. But I was always watching for low snow or iced up trail conditions.
I would also consider installing a coolant temp gauge. A lot of times, by the time the temp light comes on, it's too late.
If you're out riding and the sled seems to be holding back, like you're riding the brake, that is the first sign of the hyfax getting hot and sticking. dip off the trail immediately into loose snow and giver to throw snow up onto the track and coolers. Some guys say to pull over and shut the sled off, but at that point the sled is going to overheat even more due to lack of circulation. Best to get some much needed snow thrown up to cool it down.

It was in the high 20s on a groomed trail. Only went about 1.5 miles when it quit. I now have a rebuilt engine with new hyrax and scratchers. Took it out today and seems good. Lot of steam coming off the coolers.

Is it difficult to install a temp gauge or would a mechanic need to. I'm fairly handy but don't want to screw something up.