Who is running the bypass on there thermostat?

the gman · Nov 2, 2013

Ok last year I ran the thermostat with the bypass with a reducer in it to limit the pressure spike when the thermostat was closed. I heard some guys where running the thermostat with the bypass plugged so I installed the thermostat in my sx with the bypass plugged and I put a pressure gage on it today and found with the thermostat closed, I could build 45-50 lbs. granted this pressure is just between the water pump and the thermostat, which is mostly in the block, but seems high to me. Are you guys drilling a bigger hole in the thermostat itself to lower he pressure or are you just not worrying about it??? Allan?? Anyone.???

PalousePoo · Nov 2, 2013

Last year I drilled two 1/8" holes in the side of my KTM stat. It seemed like this allowed too much bypass. Going down a trail, my temps only ran about 120. The bypass port was completely capped off.

retired motoman · Nov 3, 2013

Blocked bypass

All the bikes I have done have two 7/64" holes in thermostat.
It easily passes air and should reduce head pressure while increasing water temp.

the gman · Nov 3, 2013

Ok we'll today I will start with one 1/8 inch hole and check pressure. What do you guys think is too much pressure???

retired motoman · Nov 3, 2013

When it leaks.

the gman said:
Ok we'll today I will start with one 1/8 inch hole and check pressure. What do you guys think is too much pressure???

You can buy radiator caps that hold pressure to 2 bars (31 lbs).
So you know the system is good for at the very least that.

I have not heard of any cooling system issues and there is a fair number of people "dead heading" the thermostat.

So any relief in the thermostat will be added safety for the system.

PalousePoo · Nov 3, 2013

I'm going to try an inline thermostat a friend bought off of ebay and didn't use. It was off a Kawasaki Ninja 250, but don't know the year. It has a small oblong hole in the side of the stat for bypass, and no other large bypass port like the KTM housing has. Those unused ports caused me problems last year, leaking coolant, while chasing motoman around priest Lake, until I double capped them. I just put the ninja and KTM stat in a pan of water and brought up the heat. The 70c KTM opens much sooner than the ninja one. So there is some street bike stuff out there that may work too. And ITS SNOWING AT MY HOUSE NOW!!!!!

the gman · Nov 3, 2013

Poo I thought you were smarter than that. Following motoman is not a good thing:crazy:. I drilled a 1/8 inch hole in the thermostat itself and get about 30-40 psi peak, and being that the pressure is in the cases mostly and reading Gary's post I am going to run it. I do have a water pump seal on order just in case but don't think the seal will see that pressure....my bike probably won't start with the battery I have anyway....

PalousePoo · Nov 3, 2013

Did you get A KTM SX for this year? The snotel is showing 12" in the trapper area. Lots of storms lining up this week, Hopefully it stays and makes the base. If it wont start, my yammi can carry us both out!! Remember the 09 dragon? ;(

the gman · Nov 3, 2013

The sled was the ****...not. Yep running a sx.hope to get out this week. Thinking maybe freeseout. Thursday...interested

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Who is running the bypass on there thermostat?

the gman

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PalousePoo

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retired motoman

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the gman

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retired motoman

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PalousePoo

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the gman

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PalousePoo

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the gman

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