Raze Heated Bars with Thermobob

tek9tim · Sep 20, 2018

I picked up a low hour 2015 FC450 that had already been set up for snowbiking with a Thermobob 3 (and other stuff not relevant to this conversation), and since all of the important stuff had already been done on it, I went for the luxury of heated bars. I want to continue running the Thermobob bypass feature in order to keep the cylinder and head at a consistent temperature, but what that means is that on the low pressure side (stator side of the motor), I'll need to have two lines return into the hose between the radiator and motor. The fittings that Raze sent me do have two threaded holes in them, but they're 180 degrees apart, and with the space constraints there on that side, I can't really see a good way to have both hoses out of the way when they're coming out of opposite sides of the fitting.

Has anybody hooked up Raze bars with a Thermobob 3? What was your solution?

needpowder · Sep 20, 2018

tek9tim said:
I picked up a low hour 2015 FC450 that had already been set up for snowbiking with a Thermobob 3 (and other stuff not relevant to this conversation), and since all of the important stuff had already been done on it, I went for the luxury of heated bars. I want to continue running the Thermobob bypass feature in order to keep the cylinder and head at a consistent temperature, but what that means is that on the low pressure side (stator side of the motor), I'll need to have two lines return into the hose between the radiator and motor. The fittings that Raze sent me do have two threaded holes in them, but they're 180 degrees apart, and with the space constraints there on that side, I can't really see a good way to have both hoses out of the way when they're coming out of opposite sides of the fitting.

Has anybody hooked up Raze bars with a Thermobob 3? What was your solution?

I’m not sure I understand. Don’t the raze bars come with a thermostat? Why would you need them both? Seems like you could just eliminate the Thermo Bob. I am not that familiar with the raze bars so I guess I don’t know where the thermostat is located.

tek9tim · Sep 20, 2018

No, the Raze bars don't automatically come with a thermostat, you can order them as a standalone setup.

The reason I want to stick with the Thermobob over the Raze thermostat is that the Thermobob bypasses warm coolant back into the engine when the thermostat is closed. This keeps the coolant moving through the motor, and keeps it at a more consistent temperature top to bottom. The Raze kit does bypass as well, but straight to the bars and that coolant loses heat in the bars and lines before it makes it back into the motor, eliminating the consistent temperature benefit of a bypass. Plus, if you're smashing through deep fluff and sweating from exertion, you aren't likely to have the bar heat valve open very far if at all, and the engine temps are likely to be low from snow contact.

needpowder · Sep 20, 2018

OK. I gotcha. There are a lot of things you can do to keep your bike warm. Obviously an engine jacket. Then stuff foam between your skid plate and engine and wherever else you can fit it. Build a plastic guard to keep your track snow from hitting the back of your engine. And finally, the most effective thing is to cover your radiators. My Enduro engineering radiator guards allow me to slip a rectangular Piece of plastic in and out whenever I need. I am constantly adjusting. Even in the deepest lightest coldest Utah days if I have both radiator covered I have to be careful not to overheat. I just adjust constantly.

GKR · Sep 21, 2018

I ran a tee in the bypass line coming off the thermobob and then two circuits, one as a straight bypass and the other thru the bars. Small ball valve on each circuit so I could run 100% thru bypass by shutting of valve to bars, 50/50 by opening both valves, or 100% to the bars by shutting off the bypass valve. I used a similar tee on the two return circuits and then into the return hose to the motor.
Works perfect.

tek9tim · Sep 21, 2018

needpowder said:
OK. I gotcha. There are a lot of things you can do to keep your bike warm. Obviously an engine jacket. Then stuff foam between your skid plate and engine and wherever else you can fit it. Build a plastic guard to keep your track snow from hitting the back of your engine. And finally, the most effective thing is to cover your radiators. My Enduro engineering radiator guards allow me to slip a rectangular Piece of plastic in and out whenever I need. I am constantly adjusting. Even in the deepest lightest coldest Utah days if I have both radiator covered I have to be careful not to overheat. I just adjust constantly.

Yup, already done all that stuff and have a temp gauge to keep an eye on engine temp. Just trying to keep my thermostat working as engineered as well as run these bars.

tek9tim · Sep 21, 2018

GKR said:
I ran a tee in the bypass line coming off the thermobob and then two circuits, one as a straight bypass and the other thru the bars. Small ball valve on each circuit so I could run 100% thru bypass by shutting of valve to bars, 50/50 by opening both valves, or 100% to the bars by shutting off the bypass valve. I used a similar tee on the two return circuits and then into the return hose to the motor.
Works perfect.

Good to hear. Looking at space on the return, I wasn't sure that a tee would lay in there if it were threaded into the fitting on the return line, and was thinking of putting a wye on there instead. Could you share a pic of your return setup?

GKR · Sep 21, 2018

Not the greatest pics but you should be able to make out what I did.

coryf89 · Sep 22, 2018

how come a MxF valve? whats with the fitting in the female end for?

would something like this work?

https://www.ebay.com/itm/1-4-Male-M...704577?hash=item44043a4841:g:xB4AAOSwHEhaAeOx

edit: or even better.. this: https://www.ebay.com/itm/1-4-Brass-...190018?hash=item1c89281642:g:2TwAAOSwOMdZS2N9

GKR · Sep 24, 2018

Those should work fine. I used the MxF because they were short for limited space and low cost. Did not have to be that configuration, thats just what I found. The valve pictured heading in to the brass T is the valve on the bypass line. The other end of the brass T is the return line from the bars.

Misha Subo · Sep 24, 2018

I'm doing the same thing to my 300 XCW. Where can I get the splice-in 3/4" in-line fitting with a 1/8NPT female thread for Tee-ing my lines that flex up to the bars and back?

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Raze Heated Bars with Thermobob

tek9tim

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needpowder

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tek9tim

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needpowder

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GKR

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tek9tim

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tek9tim

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GKR

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coryf89

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GKR

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Misha Subo

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