Overheating causes and solutions

[jambro303]

I had an overheating problem the other day for the first time and thought I'd see what you guys thought.

My buddy and I have pretty much identical sleds but mine overheated and his did not. He has a 2008 Nytro MTX and I have a 2009. We were riding up the trail doing about 30mph. It was a cold morning and the snow on the trail was frozen solid. The trail has high vertical sides for a long distance so we couldn't dive off trail. We were also both riding two up on this section but he was also dragging about a 150lb tub with gear behind his sled so it was working harder than mine. Our reversible cable style scratchers weren't doing much of anything. He claimed that my scratchers weren't putting down enough pressure which caused it to overheat. While I agree that his newer ones were doing a better job than mine, I am under the assumption that their purpose is only to get snow onto the center of the track so that the hi-fax stay cool, not to get snow all the way up onto the cooler under the tunnel/seat area. Can anyone comment on that assumption?

We stopped and let it sit for a bit and threw some snow in around the engine and on the radiator. Before we took off we cleared most of the snow from the radiator to get airflow going. But it overheated about a mile away.

Note that my buddy has not changed the coolant in his sled since he bought it new. I bought mine used last year and haven't changed it or know if it had been changed in the past. I ordered some new scratchers and figured I'd changed the coolant, but thought I'd see if anyone knows of other reasons my sled might have overheated.

 

[Mountaintech]

Good scratchers will definitely help. The track acts as a fan and will distribute the snow/ice spray throughout the whole tunnel.

 

[yamahamm]

I will buy the new ski-doo scratchers that is reverse friendly The last one on this video:

 

[larryh]

This happened to me a couple times last year and I took into a dealer and said got to be something wrong with the cooling system and left it there, he pulled it into his shop and put it on the lift and left it for a little while. When he returned he said there was huge chunks of ice falling out of the tunnel, he checked everything and it was all good. He told me that the nytro has a ice build up problem that the snow gets thrown up hits the pipes and melts, when it is really cold then the water or slush freeze's really fast and can build a ice dam around the cooler blocking snow from reaching it. Sure enough a week later it was like -10 and it overheated again, I stopped tipped it on it's side and there it was! A wall of ice right around the cooler, I chipped it out and drove a little and it cooled right down. This last fall I wanted bigger paddles and got a deal on a camoplast 2" track but there wasn't enough clearance between the track and cooler, I read on here that removing the tunnel protectors helps with ice build-up so I cut them out and the track fit with about 3/8" clearance, ran it all winter and never overheated.

 

[Mountaintech]

This happened to me a couple times last year and I took into a dealer and said got to be something wrong with the cooling system and left it there, he pulled it into his shop and put it on the lift and left it for a little while. When he returned he said there was huge chunks of ice falling out of the tunnel, he checked everything and it was all good. He told me that the nytro has a ice build up problem that the snow gets thrown up hits the pipes and melts, when it is really cold then the water or slush freeze's really fast and can build a ice dam around the cooler blocking snow from reaching it. Sure enough a week later it was like -10 and it overheated again, I stopped tipped it on it's side and there it was! A wall of ice right around the cooler, I chipped it out and drove a little and it cooled right down. This last fall I wanted bigger paddles and got a deal on a camoplast 2" track but there wasn't enough clearance between the track and cooler, I read on here that removing the tunnel protectors helps with ice build-up so I cut them out and the track fit with about 3/8" clearance, ran it all winter and never overheated.

The larger track paddles and reduced clearance between track and cooler prevent the ice wall from forming. This scenario does not occur on the mountain sleds.

 

[tapex_07]

Who was leading that day? (Original post) my guess is you were leading. On those cold, crisp, hard snow mornings, the leader usually has the hardest time keeping cool. The second guy at least has some snow that's broken up to follow in.

Yes good scratches will help, the original wire type work the best but are the least user friendly, dipping off the trail often, and if you have to drag your feet every so often.. I haven't ever had the icing issues on my Nytros, so I don't know how/what guys do to prevent it from happening.