Omitting Thermostat

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erniebearskin
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Omitting Thermostat

Post by erniebearskin »

Hi, 2014 FE350, (not sure if this question applies to all KTM 4T as well) omitting the t-stat? Upside would be better flow so slightly improved cooling, and one less point of failure? Downside would be longer warm up time and the crazy cost of those silicon hose kits.

Any opinions on this, good or bad, has anyone done this and was it worth it? Today was the first day I really looked at the cooling hoses on that bike and it's actually a pretty crude set up. :thinking:

Thanks-B
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cerealkiller
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Re: Omitting Thermostat

Post by cerealkiller »

Don't you ride in the winter Bryan? If so, that sounds like a bad idea.
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Re: Omitting Thermostat

Post by vwrally »

When I bought my used KTM 500 (I know, not a 350), the PO had installed a Samco hose kit that also eliminates the thermostat and housing. He said he did this because he was having problems with the bike often boiling over on him while sitting in traffic. I bought the bike with 39 hours on it, now has about 115. Have never noticed a single issue running without a thermostat, gets up to running temp very quickly, fan kicks on in the tight trails, has never boiled over on me, even when stuck in the muck or fighting up a gnarly hill in the summer heat. Granted, I don't run it in the winter, so that may present issues I have yet to discover. Since the fuel injection on these bikes run open loop, I don't think engine temperature is super critical, beyond some initial cold warm up enrichment. I doubt it would cool down enough while riding without a thermostat, even when running at speed, to get back into that cold enrichment zone, and certainly not in the single track trails. You'd probably notice that in your fuel mileage if it were happening, hasn't been a problem for me. With a bike you're not likely going to be cruising down the highway at 120kph in sub zero temperatures, if you are, then you'll need a thermostat, and maybe a trucker style radiator cover, lol.

Having said that, if you're not having problems with boiling coolant, I don't think I would bother with a hose kit and thermostat elimination on the 350.

Also, if I were to run my bike in the winter, I would consider the possibility that I may have to reinstall the thermostat, if the bike was running too cold and not getting out of the cold enrichment zone on the fuel map.

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axel99
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Re: Omitting Thermostat

Post by axel99 »

Delete the T-stat, you don't need it unless you ride on the lakes wide open or maybe us it for a timbersled in the powder. My bike came with smal plastic inerts to cover the rad in the winter, I only used them when riding below -15c.
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downunder366
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Re: Omitting Thermostat

Post by downunder366 »

Good question.. My KTM 350 seems to run pretty warm even with the rad fan installed mainly on the slow climbs.
Last night I ended up with a hole in one of my rad hoses so I ordered the the Samco T/Stat bypass kit which includes all Silicon rad hoses.

So I am going to try it out and see how it goes. The trail tech fan kit comes with a digital temp display so I can at least keep an eye on the temp in winter to ensure the bike does not overcool.
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erniebearskin
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Re: Omitting Thermostat

Post by erniebearskin »

Where did you order it from Ryan?
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downunder366
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Re: Omitting Thermostat

Post by downunder366 »

Blackfoot Direct, make sure you are sitting down when you price the kit out.
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downunder366
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Re: Omitting Thermostat

Post by downunder366 »

Just a bit of a follow up review of the samco thermostat bypass hose kit for my 13 KTM 350 xcf w.
I wouldn't say it helped allot with reducing engine overheat. My theory was that the thermostat and stock hoses restricted the flow of coolant.
Personally I think the best improvement was adding the radiator fan and just keep the stock hose set up.

It seems to only overheat in the really tight single track. Pretty sure there wouldn't be an issue if I was quicker in the tight stuff :blush:
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Braap791
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Re: Omitting Thermostat

Post by Braap791 »

downunder366 wrote:Blackfoot Direct, make sure you are sitting down when you price the kit out.
Agreed the samco kit is pretty sweet but the price makes them seem gold plated. I had to get a set from my 350 after having a stick poke a hole in the stock hose. Bfd had them in stock.

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dirtyboy
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Re: Omitting Thermostat

Post by dirtyboy »

I have an Orange set that is barely used for sale in the classified. Willing to take reasonable offers.

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