C3 T-Stat w/Heated bar, PST Blanket. The bike runs ICE COLD in deep snow

[matchrocket]

2018 KTM 450 Per subject. Installed the C3 Thermostat, temp gauge, and Heated bar kit along with a PST wrap. The first ride on this setup was today and we had REALLY deep snow (Pushing over the fender in places, or kicking over the bars) About 2" fresh on average. On the trail, the bike will run 170 - 180 with heated bars on full and it's perfect. As soon as I jump off into deep snow, temps plummet. 100 - 120 TOPS, and sometimes I even saw 90. YIKES. I had to run with the bars off to keep some heat in the motor.

My riding buddy on the same bike but with Carls Cycles in-house setup installed never saw below 150 all day in the same conditions.

Observations:

The Left and Right Rad get warm/hot LONG before the thermostat should open up. I have a tusk radiator cap installed and it matches temps with the TSS installed in the thermostat housing. They basically match all the way up to 180 when I let it idle in the garage. The routing of the plumbing is exactly the same as OEM, and matches the first pic more or less. The actual install pics are below. The rate of temp increase and the fact the rad cap and TSS match make me think this is not just convection.

The radiators were packed with ice. (PACKED). Is the rapid cooling is from shock cooling due to the snow load hitting the radiator or ice building up in it.?

It was recommended to me to use either a rad shut-off valve and/or radiator covers.

Thoughts? REALLY don't like the motor running this cold and I don't want to hurt it.

 

[TreewellDweller]

You know the 4” wide vertical vinyl blinds that you have on your patio door or picture window?
Cut them 4”-5” longer than your radiator is tall and slide them in between your radiator and the radiator guard.
When the temps get to high just pull one side at a time to regulate it. If you lose one just borrow another piece from the blinds. Your wife won’t mind!

 

[matchrocket]

You know the 4” wide vertical vinyl blinds that you have on your patio door or picture window?
Cut them 4”-5” longer than your radiator is tall and slide them in between your radiator and the radiator guard.
When the temps get to high just pull one side at a time to regulate it. If you lose one just borrow another piece from the blinds. Your wife won’t mind!

So , radiator block off is the way to go?

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[TreewellDweller]

It makes quite the difference on my setup.

 

[M5-]

Rad block off is mandatory. It will fix your problem.


M5

 

[needpowder]

Radiator blockoff definitely is part of the solution. I also have the front and rear of my engine blocked with various foam and random plastic. The track throws a bunch of snow on the rear of the engine.

 

[needpowder]

Cutting or tearing up a coors light box is a quick fix in the parking lot. There’s always one of those around.

 

[M5-]

I'm told a Coors Heavy box will work as well but no first hand knowledge of this.

M5

 

[matchrocket]

It makes quite the difference on my setup.

Cut up some old plastic cutting boards and trimmed the OEM radiator guards. They slid right in. Also re-adjusted my PST blanket to cover up the bottom of the left rad better and installed the cold weather portion as well. Hopefully this helps out and she runs better.

 

[matchrocket]

Radiator blockoff definitely is part of the solution. I also have the front and rear of my engine blocked with various foam and random plastic. The track throws a bunch of snow on the rear of the engine.

Any pictures?

 

[CB_Rob]

For comparison, i ran the same setup last winter and never got temp that low.
Was cold enough to need to shut down the heated bars.
Never covered the radiators.

I switched one radiator to the tunnel cooler shown in the forum, definitely cant cover it up on powder days.
Rode deep stuff yesterday and temperature was right where it should be all day 175 to 195 consistent temp.

 

[CB_Rob]

Even last year with a slapped together engine blanket it stayed warm enough as long as the heated bars were off.

 

[dooman92]

Matchrocket, Your experience is consistant with most snowbikes in that situation. If those radiators are cooler than the engine the cool coolant will fall into the engine (thru both bottom rad hoses) and extract heat and the warmed coolant will rise giving off its' heat to the rads. That is with the thermostat completely closed and no coolant flowing. It's called convection and is very effective. In the snow there is just too much cooling going on. All the aluminum of the engine and the convection effect on a frozen snow covered radiators extracts way more heat than the engine, even with the thermo closed, can generate. I have experienced your exact type temps on several occassions. Radiator covers are a big help, but in the deep powder a bib like cover of the engine worked best. A PST cover and rad covers about 75% effective. Of course on the trail gotta open up a rad or two. I cut pieces out of 5 quart oil jugs that fit tight enough between the rad and rad protector/grill that I can pull up and down and it will stay in place. Still a pia watching temps and pulling rad blocks but, helped temps. Welcome to the challenge...

 

[GlennRMK]

I have 19 Husky 450 (basically the same bike)

I have the same PST jacket but a Thermobob and when it is really deep and cold I run the extra RH PST cover. In the spring or if its setup I have to take it off.

However, in good powder I almost always have to block off the radiators. I have some thin plastic I cut up and and slide in between the stock louver and the radiator. On the deepest powder days I usually have the jacket and both radiators blocked and can usually keep it in the 160-170 range. Some days I just block one radiator. Just have to adapt to conditions.

On the other hand, those plastic louvers usually ice up. On the way back on the groomed trail I usually have to stop and knock the ice off them or she overheats. I also run a fan because low speed hardpack trails it can overheat as well.

 

[matchrocket]

Thanks all. Lots to learn.

 

[CATSLEDMAN1]

When you have to deal with the bar deep powder, 100% engine cover ( engine in a complete heavy vinyl bag ), no radiators, heat exchangers, 10 years ago my riding group went through that transition. Insulation is unnecessary, just 100% aluminum engine cover so the dry fluffy snow cannot touch engine parts, then you can run up against the termo stat, uphill, downhill idling through the deep stuff, spring snow, same setup and good engine temps.

 

[CB_Rob]

When you have to deal with the bar deep powder, 100% engine cover ( engine in a complete heavy vinyl bag ), no radiators, heat exchangers, 10 years ago my riding group went through that transition. Insulation is unnecessary, just 100% aluminum engine cover so the dry fluffy snow cannot touch engine parts, then you can run up against the termo stat, uphill, downhill idling through the deep stuff, spring snow, same setup and good engine temps.

Do you have a pic of the setup?

 

[CATSLEDMAN1]

I don't have a picture to post , will take one next week end, old posts about best material to build engine covers, we have ended using truck tarp vinyl, easy to work with, holds up, easy to modify, put grommets in and hold the cover on with bungie balls or what ever they call them. No fashion statement but effective. Mine is one big piece that goes under the motor. Tarp glue and you can add panels, to add and subtract as you perfect your set up. Local shop that has real snobikers, has morphed over to similar setups after selling a lot of expensive and attractive covers and could not maintain heat either.

 

[M5-]

This is the stuff we use, its cheap and works well. Eventually it will melt if its right on your pipe but header wrap fixes that or just let it melt and self clearance. Add grommets, ball bungees and go. Make a few sets and just replace them when they get ratty. You can really overthink it and over spend on snow bike stuff. Keep it simple.

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M5

 

[CB_Rob]

When you have to deal with the bar deep powder, 100% engine cover ( engine in a complete heavy vinyl bag ), no radiators, heat exchangers, 10 years ago my riding group went through that transition. Insulation is unnecessary, just 100% aluminum engine cover so the dry fluffy snow cannot touch engine parts, then you can run up against the termo stat, uphill, downhill idling through the deep stuff, spring snow, same setup and good engine temps.

You've been doing HX instead of rads for a while?
I'm trying it this winter, hope to leave the engine blanket on year round and never over heat.
Never had a problem with underheating as long as i had some sort of wrap and didn't turn on the heated bars.