##2021 Season Low snow mod update-video##Another (better?) no weld solution for tunnel shortening.

[b-litt]

Mine with this set up is running very hot too. I’m hit going down the trail though. Gets to 160 fast and have to chainsaw her in on the side of trail. It still takes significantly longer to cool off when doing this than it did my cut and welded tunnel. Maybe I have an air bubble too? I didn’t drill the holes and have a wrap on the tunnel.

I’m about to throw in the towel and weld. I really don’t want to. The difference in snow and ice on the running boards is as big of an benefit as the shorter tunnel. I think I’ll suspend the front end and run it with the coolant cap off to see if it helps. I’m hesitant to drill holes. If I have to go the weld route I’d be stuck with it as an auxiliary cooler. Those holes with out the cooler in there would not be cool!

 

[live2beel]

I have one of these coming from CR Racing, I will post the results once installed. To me it was the best of both worlds.

 

[Sheetmetalfab]

The same way when the ground is warm and the mountains get pounded with snow it actually will insulate the ground and keep it warm causing avalanches. The fins on the cooler are holding the snow in it, cool air from track movement and additional snow getting thrown up getting more and more packed in caused the snow to melt and freeze right away, then insulate the cooler. This could be just the type of snow I was in, but this is just what my experience has been. I know there are several out there that have had good luck going this route.

Also, there are no air bubbles in the cooling system. Yes I have bled them out, Yes I have checked the coolant level several times, No I am not some Joe-Blow off the street that half-a$$ed my work.

I’m just wondering if your experience is the exception not the rule........

Something must be different on your sled if so many other sleds have no issues.

(My brothers sled runs around 105 degrees in deep snow with only the mtntk 5’ cooler)

 

[HECKS]

Vector, are you running the stock track ?

 

[nibrandon]

To update all on my experience from earlier in this thread: I have done everything I can to remove any air bubbles (front end high, right side high, pulling vacuum on the system, etc....), so I dont think that was the issue, and it still runs very hot on the trail (140-180). I have ended up having dual scratchers on the skid and adding ski scratchers (so I have 3 per side). Off trail, it runs cool (95-100). On trail, I have to keep my speed up and look for the loosest snow on the trail. No icy trails or slow wooped out trails for me, without taking cooldown breaks. I see this as a temporary fix to get me through the season, and will weld it up for next year.

 

[nibrandon]

Just to clarify, I would love to find a solution to make this work, but am out of ideas. Also, no criticism to Murph, it must work on some sleds, just not mine apparently.

 

[pepperhouse]

Mine does the same
Hot on trail, have to constantly chainsaw to get it off high temp.
When you hit first patch of fresh snow it gets even hotter for first 5-10mins.
Then it will finally drop and be good rest of day in the fresh til trail out.

Hooked up the factory coolers with a tunnel cut kit after last ride Thinking that should fix it.

 

[Sheetmetalfab]

Do you guys have a kink in your clutch side coolant hose?

 

[b-litt]

I know there are no kinks or tight bends in the coolant hoses on my sled. Was very careful about that. Could it be that the coolers are maybe welded thicker on some causing flow issues. I’ve seen different temps from similar sleds with welded cut jobs, and have assumed this could be the reason.

I’m fine off trail 95-100 and 160 on trail with
good scratchers and snow flap.

Wondering if I could test flow somehow? Probably not...

 

[b-litt]

BTW I know it works great on Murph’s sled. I’ve seen it first hand last year. Ran as cool or cooler than one of the stickers in the group. Which is what convinced me to give her a go!

 

[Murph]

Also, no criticism to Murph,

No worries. I wasn't offended by you or anyone else's experiences.
Just trying to find a common denominator as to why some sleds continue to run hot.

 

[ullose272]

Im not even running a flap, sometimes gets warmer 120-130 on trail. Quick dip off trail fixes it usually

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[shattuck]

No worries. I wasn't offended by you or anyone else's experiences.
Just trying to find a common denominator as to why some sleds continue to run hot.

The weight of the rider will play into this and the steepness of the trail. I believe these will both be huge factors the harder you work the motor the more heat you will generate.

 

[nibrandon]

Do you guys have a kink in your clutch side coolant hose?

I will doublecheck, but I dont believe so. Riding tomorrow, but it won't be an overheating day (its stupid deep). Will check the coolant line next week.

I have a cut tunnel and no flap. 160lb rider. 162 X3 track. I honestly think the issue is just not getting snow to the center of the tunnel unless the scratchers are spraying tons of snow. The track does nothing to spray snow up there on the trail. It gets it on the outside edges where the stock cooler is, but the center doesn't see as much.

In retrospect, even if I have to weld the tunnel, this mod was worth cutting my tunnel, which was the initial goal. That mod is a gamechanger on this sled. It doesn't stop digging.

 

[Snappy Sledder]

Sled setup is as follows:
2021 Khaos 850
165x2.78 Track
QD2
SLP Can
Skinz Headlight Delete
7" tunnel cut and tapered
Factory swiss cheese snowflap installed back on

I did wonder about kinked coolant lines, so after a few heat cycles I checked and they were good, as well as pulling the tank off again last night to check they were not kinked one bit. I am also curious on the flow, that if it is restricted inside the cooler more than factory that slower speed off trail is not allowing the coolant to flow through as much which would in turn not get adequate amount of cooling to the engine? Buddy's sled I was with has a 2019 850 Pro 155x3 with no tunnel cut, swiss cheese flap, TKI geared down belt drive, SLP can, and was running around 150 on the trail and 98-105 off trail. I'm thinking b-litt might be onto something with the flow theory.

 

[nibrandon]

Update: I checked for kinked lines and didn't have any, but since I had the time and it partially apart I changed the hose configuration and put new fittings on to make the coolant path an easier sweeping flow. Purged all the air out and went for a ride.

I rode it yesterday on a whooped out trail and it performed the same, so I dont think it was the lines. I did notice if I chop the throttle instead of keeping a constant "cruise control " throttle position it seems to cool better. I think this is due to the center lugs holding snow and throwing it up on the center cooler better when the track is spinning. The track has to spin though, not just speed up. I know it sounds dumb, but I was able to make it all the way back to the truck by doing this without stopping. On the same trail on the way up I had to stop twice to put snow on the tunnel to keep temps below 190.

I have an X3 track, not the stock polaris track. Maybe it doesn't cup and hold snow as easily and throw it up in the center of the tunnel? Anyone else think of any similarities? It really seems to be an issue of getting snow to the center of the tunnel for my sled. The scratchers help, but whooped out trails make it tough for them to be effective.

 

[Nils]

Update: I checked for kinked lines and didn't have any, but since I had the time and it partially apart I changed the hose configuration and put new fittings on to make the coolant path an easier sweeping flow. Purged all the air out and went for a ride.

I rode it yesterday on a whooped out trail and it performed the same, so I dont think it was the lines. I did notice if I chop the throttle instead of keeping a constant "cruise control " throttle position it seems to cool better. I think this is due to the center lugs holding snow and throwing it up on the center cooler better when the track is spinning. The track has to spin though, not just speed up. I know it sounds dumb, but I was able to make it all the way back to the truck by doing this without stopping. On the same trail on the way up I had to stop twice to put snow on the tunnel to keep temps below 190.

I have an X3 track, not the stock polaris track. Maybe it doesn't cup and hold snow as easily and throw it up in the center of the tunnel? Anyone else think of any similarities? It really seems to be an issue of getting snow to the center of the tunnel for my sled. The scratchers help, but whooped out trails make it tough for them to be effective.

Your theory might make sense but if you're going to compare the two techniques you should be going uphill in both scenarios. I always struggle with keeping temps going onto the mountains on trail, not coming back. Guess that's natural given the very different engine loads.

 

[ullose272]

I just put a 156 x3 track on my sled and it runs ALOT warmer than the 2.6. 6" cut, no flap, fine in powder but warms up quick on trails. Going to try with a flap.

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[nibrandon]

Yes, thats a good point about going uphill and running warmer because of it. I did notice a drop in temperature while still coming out in the evening between when I wasn't chopping the throttle and when I was, so I still think there is something to it.

Good to see other feedback on the X3. That might be a contributing problem for me.

 

[Sheetmetalfab]

Your theory might make sense but if you're going to compare the two techniques you should be going uphill in both scenarios. I always struggle with keeping temps going onto the mountains on trail, not coming back. Guess that's natural given the very different engine loads.

I think it also has something to do with snow and ice buildup on the sled.

Heat sink effect on the way back to the truck.