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Coolant heated handle bars

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Oct 12, 2017
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Toronto
This pic shows the flow through the radiator as I understand it (for my KTM 300 XCW). As you can see my plumbing has a stock thermostat. When the engine is cold, the blue circuit starts at IN (coming out of the head) and short cuts down to the pump at OUT.

When the bike warms up, the thermostat opens and the red circuit is now the path for the coolant, getting carried up to the top and then down through the radiators, eventually down again to the pump below by existing at OUT (btw the radiator on the left is not present in this photo).

My question is: where do I connect the two lines for my heated handlebars? Free pizza for the right answer...:pizza:
 

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n16ht5

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Aug 5, 2013
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So I did the DIY heated bars.. but now my bike overheats on the trail. NEVER EVER did before. I am thinking too much coolant is bypassing the rads and just circulating through the bars? I used 3/8" line and 1/4" NPT-3/8" barbs. I was thinking to put a valve inline but don't want to restrict the flow too much when the Tstat is not open.
 

byeatts

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Nov 29, 2007
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So I did the DIY heated bars.. but now my bike overheats on the trail. NEVER EVER did before. I am thinking too much coolant is bypassing the rads and just circulating through the bars? I used 3/8" line and 1/4" NPT-3/8" barbs. I was thinking to put a valve inline but don't want to restrict the flow too much when the Tstat is not open.

No the bars are an additional place to lose heat as well as system holds more coolant, Ewe have something wrong and the bars are not makings system run hotter, If anything the bars make it harder to get up to temp assuming you hooked up properly.
 

Sheetmetalfab

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Oct 5, 2010
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……..
So I did the DIY heated bars.. but now my bike overheats on the trail. NEVER EVER did before. I am thinking too much coolant is bypassing the rads and just circulating through the bars? I used 3/8" line and 1/4" NPT-3/8" barbs. I was thinking to put a valve inline but don't want to restrict the flow too much when the Tstat is not open.

Bubble of air in your system.
 

dooman92

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Heated bars

Does the hot coolant go to the bars first then return via bypass at tstat? Returning coolant cooling down thermo and stays closed too long? Just a thought, doesn't seem easy to reverse flow but, can't see your setup.
 

wellfed777

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bringing this thread back around

so how are folks liking there homemade coolant heated bars
any lessons learned over the past season ?

thanks i'm planning on doing my bars this season
 

Sheetmetalfab

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……..
bringing this thread back around

so how are folks liking there homemade coolant heated bars
any lessons learned over the past season ?

thanks i'm planning on doing my bars this season

My home made bars worked ok.

Definitely the crossover tube is required. (Didn’t get warm enough without it)
 
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2smokin

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Anyone running these on a 300 know if 130 degrees from my thermobob will be hot enough after heating the carb as well?
 

CATSLEDMAN1

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Nov 27, 2007
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130 temps

Anyone running these on a 300 know if 130 degrees from my thermobob will be hot enough after heating the carb as well?

On my 500 xcw I often leave the truck and immediately take off on some tight trails and my engine temps are only barely over 100 degrees, even at those temps if my ball valve is wide open controlling flow to the bars, they get blistering hot, you can't stand unrestricted flow 130 degree anti freeze very long.
 

2smokin

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On my 500 xcw I often leave the truck and immediately take off on some tight trails and my engine temps are only barely over 100 degrees, even at those temps if my ball valve is wide open controlling flow to the bars, they get blistering hot, you can't stand unrestricted flow 130 degree anti freeze very long.
Interesting, i think the 300 may flow less coolant. I have it all set up with no valve on c3 bars, and its nice but in no way blistering. my bypass does heat my carb first but even ripping through the trees at 140 its just nice and warm not hot. I would say its enough though, maybee not for -30 but those days hurt either way.
 
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