Yeti tunnel cooler

Chadx

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understandable, However they are trying to prevent the overheating which is being created by the Selkirk system .We found this to be the issue and none of our 60 builds have any heating issues, To be informative we need to identify the cause of the problem.
I only speak for myself and my setup, but I disagree that the overheating is "created by the selkirk system". It's caused by there not being a cooling system on my snowbike that can cope with all situation. That would be air-cooled radiators. In my case, I also have the selkirk and neither of these can cope with all the situations I encounter on a typical ride, but a tunnel cooler could. If I did not have the selkirk and, instead, bundled up the engine with any type of engine cover complete enough to keep out the snow in cold in deep powder, I'd run into the exact same situation; the radiators would not cope. I've already outlined the riding situation I'm talking about (the two main being riding whooped out trails where speeds are too slow for radiators to get enough airflow and during long up hill deep powder pulls where there is little powder cooling anything and again speeds are too slow for radiators to do anything). And, I don't want to cover, uncover, cover, uncover radiators and engine flaps off and on all day. Hence my interest in a C3 tunnel cooler and the topic of this thread. There are plenty of other threads to talk about why and when and how to wrap, protect, cover, engine and radiators, etc. so we might as well (me included) keep that chatter in those threads so this thread can focus on the C3 heat exchanger as most of us that are considering a tunnel cooler are already well versed in various engine covers, radiators covers, rear engine covers, wrapping heated bars, alternate setups (like the selkirk), etc. We must agree that all regions and rider experience vastly different conditions and it even comes down to riding style and terrain. So one size does not fit all. Some of us experience situations where a tunnel cooler would make our snowbike experience better.
 

byeatts

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I only speak for myself and my setup, but I disagree that the overheating is "created by the selkirk system". It's caused by there not being a cooling system on my snowbike that can cope with all situation. That would be air-cooled radiators. In my case, I also have the selkirk and neither of these can cope with all the situations I encounter on a typical ride, but a tunnel cooler could. If I did not have the selkirk and, instead, bundled up the engine with any type of engine cover complete enough to keep out the snow in cold in deep powder, I'd run into the exact same situation; the radiators would not cope. I've already outlined the riding situation I'm talking about (the two main being riding whooped out trails where speeds are too slow for radiators to get enough airflow and during long up hill deep powder pulls where there is little powder cooling anything and again speeds are too slow for radiators to do anything). And, I don't want to cover, uncover, cover, uncover radiators and engine flaps off and on all day. Hence my interest in a C3 tunnel cooler and the topic of this thread. There are plenty of other threads to talk about why and when and how to wrap, protect, cover, engine and radiators, etc. so we might as well (me included) keep that chatter in those threads so this thread can focus on the C3 heat exchanger as most of us that are considering a tunnel cooler are already well versed in various engine covers, radiators covers, rear engine covers, wrapping heated bars, alternate setups (like the selkirk), etc. We must agree that all regions and rider experience vastly different conditions and it even comes down to riding style and terrain. So one size does not fit all. Some of us experience situations where a tunnel cooler would make our snowbike experience better.
Good info , oddly the 450 riding in Arizona in 90 plus temps full throttle and in sand hill climbs and slow knarly we don't even see this overheating . You may try getting the headpipe opened up, You will likely see your issue solved.
 

Chadx

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You may try getting the headpipe opened up, You will likely see your issue solved.
That would only solve the issue in a very specific situation but introduce way more issues than it solves. A tunnel cooler will resolve the occasional heat issue but without the side effect of keeping temps too low in many conditions because snow and cold will get in through the opening by the headpipe area. It really boils down to wanting a 'set it and forget it' setup, like a snowmobile. The only way to get that is covering the engine as completely as possible and using a thermostat and tunnel cooler. Can I have ideal engine temps for the vast majority of my riding with less than that? Yes, and I have that now and have had that on my previous builds. But I want more than "the vast majority of time"; I want that all the time. Enter the tunnel cooler.

Please believe that I've enough experience and am analytical enough to have already worked through what does and does not work for my riding style, riding area, riding conditions and preferences and "getting the headpipe opened up" is not it.

A tunnel cooler is the next step to take my snowbike build from 90% perfect to 95% perfect.
 
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RmK8oo

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I'm running a Selkirk kit on my 18 Husky 500 with a C3 194 tstat, PR2 tuned Vortex and Yeti 129 kit. I put about 60 hours on it last year in the Snowy Range, I never experienced any overheating issues,. I run the kit fully closed when off trail and take the front cover off if running further then a couple miles down the trail. I've never had to remove either of the side covers other then to change oil. I should clarify, I have not ridden in spring conditions or much above freezing. Bike has a voyager pro with a temp sensor in the tstat housing, temps stay between 180-200 in the trees and on trail. I ride the bike aggressive in the timber and very easy every else between. I am very pleased with the Selkirk kit.
The weight thing is of no real concern to me. When taking everything else I carry on the tunnel into consideration (Yeti can, Pelican case with food, beverages and shovel)not to mention my Avy bag with extra gloves, goggles and another shovel, sometimes a drone too) a few extra lbs isn't for me to worry about. I always think to myself, if I get to a super nasty climb or whatever else, I'll stop and unload the
Yeti can and Pelican case in the trees and drop a pin on my GPS to grab it later, but I've never actually unloaded anything no matter how gnarly the terrain has gotten, I just let it rip! Would the bike do better with less weight? There is no doubt it would perform better with less weight, but it does everything I want it to do with the extra weight.

Some people seem to just hate certain products and take every chance they can to bad talk what they don't like! Whatever floats your boat, but come on it gets old!

Fact is no bike built to date was engineered to be in the snow turning a track plain and simple. There's been a lot of engineering by many people to help dirt bikes perform well in the snow, but until there is a purpose built bike manufactured, everything will always be a work in progress. There's no one product that will make a perfect snow bike. It's up to the individual to put together a combination that works well and there always seems to be a compromise no matter the setup.
I will say I have no plans of ever buying another sled! Love my bike! Do I want more power? Hell yes, but nothing I've ever built or owned ever makes enough power after riding or driving it for a bit, you always want MORE!
Just my $.02
 
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Sep 18, 2018
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I used a 1 1/8" hole saw to cut the fitting holes.
 

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Chadx

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Outstanding! Thank you for sharing so many images. Not so scary after seeing.

I did notice that the hoses were strapped to the moving portion of the strut/shock. I know it only moves a small amount, but will the hoses flex enough to accommodate that much movement without pulling off the fittings? Or do they have a bit of slack in them? Just curious as it's hard to tell from one image. Guess onced they are warmed up, they will be more flexible so probably more than enough.
 
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CB-BLR

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Do any of you have experience with the MTNTK Performance tunnel cooler for a Timbersled?

I have used their snowmobile ones with great success on my past sled.

Chris
 

dooman92

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Snowscooter5, thanks for the great photos. It appears you did not have to cut out any bracing as was mentioned as a possible issue. So no brace cutting? Thanks again.
 
Sep 18, 2018
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@Chadx thanks for the note about the hose flex. I will double check that there is enough slack. The pic is taken at full droop so the hoses should flex with the S shape.

@dooman92 The brace that everyone keeps talking about is on the bottom side of the tunnel. For 2020 they added an aluminum strengthening plate that is epoxied to the backside of the tunnel where the fitting poke through. You have to drill through this which does weaken it however the cooler fits just fine.
 

dooman92

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Snowscooter5, thanks for reply. I am evaluating my yeti tunnel for options. Your cooler looks to be about 1/2" thick or less?? Where the cooler ends I only have just over 1 1/2" clearance. I'm wondering how thick of a cooler would work without rubbing. Any thoughts?
 

Chadx

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Snowscooter,
I was going to IM some questions but figured everyone may benefit from the answer, so just going to post here. I'm going to go ahead and order a tunnel cooler. Curious if any of the other parts you needed for the install you purchased from them. I already have a pretty C3 heavy setup including the thermostat, heated bars, etc. so my setup will be very similar.

Looks like a person needs hoses that are 1" inside diameter, correct? I'm fine with black hose since it won't show on mine behind my shroud. I'll have to decide between silicon and regular heater hose. For the U shaped piece coming off the C3 thermostat and running backwards, I don't think a regular radiator hose would do that without kinking. Your U shaped piece looks like a silicon U shaped piece. Where did you source that? And where did you source the straight length of hose (which looks different than the U shaped bit) and also what fittings did you use (brass, plastic, etc.) and source? Trying to get my shopping list together when I order from C3 and will ask them what all they carry of what I need. Rather than making a U-turn with the hose off the C3, I might look running the thermostat hose forward and wrapping all the way around the cylinder head and going back on the left side of the bike. I think any hose could make that radius without kinking and then I could use one piece with no splices. I have some planning to do...

Does the cooler come with basic instructions like what I.D. hoses, what hole size to drill, what to unbolt to fit it or did you just figure it out as you went? Doesn't look complicated, but just curious. Re-reading your posts, see that you drilled 1 1/8" holes and unbolted the entire suspension to give working clearance.
 
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shortstuff

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Do any of you have experience with the MTNTK Performance tunnel cooler for a Timbersled?

I have used their snowmobile ones with great success on my past sled.

Chris

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