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Thermostat Temp

Talk about surprising obscure info; good find!

Every other vehicle I've looked at had thermo's in the 170 - 195F range.
 
I would say it’s a good thing and expect with the lower thermostat temperature the entire system would be more uniform and reduce rapid thermal changes.

Efficiency with the minimal size of the cooling systems especially with the heats that are generated is impressive.
 
So it's pretty much always open after warming up. So it's just being used to get warmed up quickly. Then the intention is circulation of coolant always during all other operation. Probably a good idea for an aluminum engine to keep consistent temperatures. Agree with 2andblue that it allows for designing the cooling system with less capacity if hot spots aren't allowed to develop, which I would expect if the thermostat closes while riding even on a cold day.
 
I'll try and play.

On the Kaws owned by me there is no bypass built in for the cooling system. I'm assuming the 1400 engine is the same. Perhaps the lower temp is a sort of cobbled work around to deal with this shortcoming?

Some have installed a Thermo Bob bypass kit on their C-10, KLR, or Versys for better temperature control and to cut the inrush of cold coolant to the cylinder block area. I've installed one on my 650 Versys.
 
I'll try and play.

On the Kaws owned by me there is no bypass built in for the cooling system. I'm assuming the 1400 engine is the same. Perhaps the lower temp is a sort of cobbled work around to deal with this shortcoming?

Some have installed a Thermo Bob bypass kit on their C-10, KLR, or Versys for better temperature control and to cut the inrush of cold coolant to the cylinder block area. I've installed one on my 650 Versys.

I have to agree with you Steve. That was the conclusion I came to. 140* is pathetic. Should be at least 180 IMO. I think this was the workaround for suppressing cycling when used in cold climates. It's not efficient, not good for the oil or rings sealing, and would be alot better with a bypassing system.
Steve
 
I have to agree with you Steve. That was the conclusion I came to. 140* is pathetic. Should be at least 180 IMO. I think this was the workaround for suppressing cycling when used in cold climates. It's not efficient, not good for the oil or rings sealing, and would be alot better with a bypassing system.
Steve
But then you have Cliff's bike with almost a quarter miles on it still performing well and my old c-10 that was still performing well with excellent compression and no oil burning at 234k miles when I sold it and last I heard was over the 250k mark. I was running a 190-195 Stant Superstat in the Connie for smoother control of temp cycling.
 
But then you have Cliff's bike with almost a quarter miles on it still performing well and my old c-10 that was still performing well with excellent compression and no oil burning at 234k miles when I sold it and last I heard was over the 250k mark. I was running a 190-195 Stant Superstat in the Connie for smoother control of temp cycling.
In stock form, with a thermostat temp of 140 and a fan on temp of 205, there's a possibility for a 65* swing in coolant temps on an warmed up engine. Now in the real world around let's say 90*, I would guess most c-14's are running +180* so the low thermostat temp isn't an issue. The real problem is in cooler temps when the ambient air can really suck the heat off the radiator. I'm not talking riding in frigid weather, 70* would for sure have the engine operating cooler than what's best for it.
As you know Steve, we tend to think "differently" from other folks regarding engine temps. In fact, it might be interesting if you share what you noticed going from the stock thermostat ( 170* IIRC?) in your c-10 to the 195* thermostat.
Steve
 
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140F That is down right frigid for a modern gasoline engine, I had no idea. That certainly explains lower fuel mileage in cooler weather. Under some conditions that could even lead to sludge formation. What is optimal operating temp for the C14 and is there a thermostat available to do the job?
 
That certainly explains lower fuel mileage in cooler weather.
Another factor is our C-14’s are fat and twin that with the principal cooler air is denser and the negative effect on aerodynamics is strong.

Flying RC airplanes for years and the difference between warm air flying and cold is remarkable, cold air being dense can keep planes afloat at slower speeds. This is at sea-level. Preferred trining, buddy boxing newbies, on cooler days as landings can be so much slower, stalling less of an issue and recoveries easier for training pilots.

Effect on our fat ninjas of cooler air is the power plant is required to develop more energy to push through the air - especially at highway speeds.
 
In stock form, with a thermostat temp of 140 and a fan on temp of 205, there's a possibility for a 65* swing in coolant temps on an warmed up engine. Now in the real world around let's say 90*, I would guess most c-14's are running +180* so the low thermostat temp isn't an issue. The real problem is in cooler temps when the ambient air can really suck the heat off the radiator. I'm not talking riding in frigid weather, 70* would for sure have the engine operating cooler than what's best for it.
As you know Steve, we tend to think "differently" from other folks regarding engine temps. In fact, it might be interesting if you share what you noticed going from the stock thermostat ( 170* IIRC?) in your c-10 to the 195* thermostat.
Steve
When I went to the 195* stat the engine ran quite a bit "sharper", more responsive to throttle inputs. The cooling fan with a lower cut in temp had no problem keeping things cool in the FL summer heat. I commuted on it virtually every day that was not below freezing back when I had to do that worksux thing.

As mentioned earlier, the SuperStat really smoothed out the cold weather cycling of the coolant temperature and kept the coolant nice and warm in the winter. Not perfectly smooth but greatly mitigated the temp swings.
 
Ok that brings up a dumb question.
Doesn't the same Cooler/denser air allow them to make more power?

Ride safe, Ted
Steve or others would need to comment there.

The programming of the ECU I would expect would maintain a consistent Air / Fuel ratio. That said since cold air is denser would expect some degree of extra squish but not enough to overcome the constant which is the drag on the bike.

Kind of drifted off course on this thread, oops.
 
The point of my comment although not really supported by any hard data only casual observation is that because the engine operating at the mentioned cool temp is running a richer A/F ratio therefore fuel mileage is decreased. That being said I will share my non scientific method upon which I base my conclusion. On the same relatively flat stretch of highway and believe me relative is the key word in my finding, at relatively the same speed using a Throttle Meister locked with the only change being a relative 30F increase in temp 45/78 I observed at the lower temp in the morning a "current" mileage on the display less than the "average"
and in the afternoon a "current" greater than "average" +/- 4 MPG. There you have it.
 
I think that in dense and/or cool air the A/F Ratio becomes leaner as there is more air/oxygen in each intake stroke, and the fuel is relatively constant. I only asked the question is response to 2andblues statement about it being more difficult to push thru the dense air.
ie; Yes it is more difficult, but we have {some} more power available to do so. (My apologies for moving from his question)

Getting back to Steve's discussion.
I think the purpose of the 140* thermostat is to initiate coolant movement as soon as the engine is at a reasonable operating temperature.
By coming on early, it prevents hot spots in the engine/coolant that have to cycle out.
The actual operating temperature of the engine is controlled by several things.
Some are the rate the water is circulated, the size/efficiency of the radiator, the load the engine is under, the amount of air movement, and the fan on temperature. All work together to efficiently control the temperature of the engine.

Last; Our bikes {and our vehicle's} have a warm up cycle in which the engine runs at higher RPM's until it reaches operating temperature.
I suspect the 140* thermostat works with the computer to make this happen smoother/quicker.

Ride safe, Ted
 
When I went to the 195* stat the engine ran quite a bit "sharper", more responsive to throttle inputs. The cooling fan with a lower cut in temp had no problem keeping things cool in the FL summer heat. I commuted on it virtually every day that was not below freezing back when I had to do that worksux thing.

As mentioned earlier, the SuperStat really smoothed out the cold weather cycling of the coolant temperature and kept the coolant nice and warm in the winter. Not perfectly smooth but greatly mitigated the temp swings.
SteveJ Where did you get your Stant SuperStat thermostat ? And any part numbers would be helpful . Thanks Floyd
 
I posted about the 140 degree thermostat years ago and got no responses, if I recall correctly.

I know of no other MC that has anything less than a 180 degree thermostat. I believe 180 degrees is the most common. Why Kawasaki uses a 140 degree thermostat is beyond me. At first I thought that 140 degree might be a typo, but no, I verified it's actually a 140 degree stat when I did my valve check & adjust last year.

I replaced it with a 160 degree stat - I probably should have installed a 180 degree.
 
Let us know if you notice anything different. I don't think we have an answer to this burning question,,,, yet.
 
I posted about the 140 degree thermostat years ago and got no responses, if I recall correctly.

I know of no other MC that has anything less than a 180 degree thermostat. I believe 180 degrees is the most common. Why Kawasaki uses a 140 degree thermostat is beyond me. At first I thought that 140 degree might be a typo, but no, I verified it's actually a 140 degree stat when I did my valve check & adjust last year.

I replaced it with a 160 degree stat - I probably should have installed a 180 degree.
Yamaha FJR1300 (160°).
 
No difference with the 160 degree stat after the bike is warmed-up. With the 160 degree stat, it may take less time to warm-up , but I'm not certain of that.
 
For Emissions, the thermostat does not control the cooling temperature it just controls the flow of coolant through the engine and radiator. Remove the Thermostat out of an older car without electric thermostat-controlled fans and it will run hotter and usually overheat. Why cause the continuous flow of coolant through the radiator without time to stay in it to transfer the heat to the atmosphere it's just rushing through.

in modern cars, bikes, and trucks Once the liquid climbs to temperature the thermostatically controlled fan switch is set for both fans to come on to pull air through the core. and they control it that way. Want a more responsive engine with cooler intake temps run a 180 but in modern emissions, it's colder thermostats, it's all about lower levels of combustion by-products that come out of the tailpipe

It's all about combustion chamber temperatures most vehicles today run as hot as 215 /220 Higher coolant temperatures reduce ignition delay and premix burn during combustion and a more complete burn
 
My C-10 had the Thermo-Bob installed, and the coolant temp stayed rock steady once
up to operating temps in any ambient temperature. (1/3 off cool on the gauge) It would only
climb further in slow or stop and go traffic. The temperature gauge without the thermo-bob on
cooler days would barely move past the 1st line on the gauge while moving.

I can say without a doubt, Thermo-Bob controlled coolant temps much better than the OEM setup.
 
For Emissions, the thermostat does not control the cooling temperature it just controls the flow of coolant through the engine and radiator. Remove the Thermostat out of an older car without electric thermostat-controlled fans and it will run hotter and usually overheat. Why cause the continuous flow of coolant through the radiator without time to stay in it to transfer the heat to the atmosphere it's just rushing through.

in modern cars, bikes, and trucks Once the liquid climbs to temperature the thermostatically controlled fan switch is set for both fans to come on to pull air through the core. and they control it that way. Want a more responsive engine with cooler intake temps run a 180 but in modern emissions, it's colder thermostats, it's all about lower levels of combustion by-products that come out of the tailpipe

It's all about combustion chamber temperatures most vehicles today run as hot as 215 /220 Higher coolant temperatures reduce ignition delay and premix burn during combustion and a more complete burn
I wonder if there is something odd with the stock ignition timing that is emissions related?
Some people report lower temps with a tune, may be due to timing changes? IDK
 
SNIP ....... Remove the Thermostat out of an older car without electric thermostat-controlled fans and it will run hotter and usually overheat. Why cause the continuous flow of coolant through the radiator without time to stay in it to transfer the heat to the atmosphere it's just rushing through.
SNIP .......

The physics of a radiator is that with a higher the flow, the greater the heat transfer. Heat transfer dos not increase at a lower flow even tho the fluid spends more time in the radiator with a lower flow. This may seem counter intuitive, but that's not how radiators work.

Radiator Curves.jpg
 
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SteveJ I was reading the thread about thermostats, I know, it's been a little while. I couldn't be sure from the conversation which Connie your thermostat link applies to. Is it for a C10 or a C14? Is it still doing the job well and was is difficult bleeding the system without a vent in the disc? The photos shown on Amazon don't show a bleed vent. TIA

th.JPG
 
Not trying to be a super-star just trying to help shed light on this so that you can make a better decision if you ride in cold, thought about the low-temperature thermostat for the last year and being on the fence of reasons why!

Ride every day in weather down as low as 30 degrees and as high as the upper nineties here in SC.
In the winter I block half the Rad with Cardboard that keeps my engine temperature in the upper 190s, and below is why.
last year was my first with the Concourse as my daily driver and developed a suspicion while looking at the cloudy oil during a change,
sent an oil sample to Blackstone and the results were alarming being elevated water ( Water is a by-product of combustion) and metal exactly what I thought, running a cold engine. Attached is an email from an engineer contact who works for Mahle engine parts in cooling systems.

He thumbed it down well for me.
hope it helps you with this in wintry weather riding!
 

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Here's what's in the above email. HTH

Cooling Large displacement motorcycle engines

Sent: Monday, January 22, 2004 10:00 AM

Tec jeff Celentano

Subject: Re: Large displacement motorcycle engines

Motorcycles use a system modeled like the Rotemp style thermostats that open at a lower water temperature than what we consider normal to help prevent temperature rise By sending the coolant to the radiator early, it starts cooling before the water temperature rises and prevents spikes and boil over and hot pockets. This type of system works in vocations needing a large heat shedding radiator and no place to package it

This has the merit of suppressing overheating by circulating the coolant water to the radiator from the low water temperature, With a warmer thermostat it would never cool proper in warmer climates trapping coolant in the engine block until 190 would lose control of cooling physics, On the other hand, it is known to cause overcooling especially in winter season because it starts circulating when the engine is not sufficiently warmed up if this tendency is noticeable, it may be necessary to take measures such as blocking part of the radiator or using an elevated temperature thermostat during the winter season. Sending you white papers that really explains what we found out years ago on a V-Max and what Porsche found and solved using vortexes in the V-rod cooling systems.

Two Months to go and welcoming warmer Daytonal

Thanks!

Vihaan

From: Jeff Celentano <jce

Sent: Monday, January 21, 2004 9:59 PM

@matorsports.support.mahie.ap

Subject: Large displacement motorcycle engines

HI Vihaan, been pondering this question for months, thought, think, doubt, but you know we tend to overthink and lose the facts that we already know!

The trend with Kawasaki and other brands of large displacing motorcycles is low temperature thermostats, Example my daily 1400 cc thermostat opens at about 144 degrees During warm months no issues the bike out on the highway in ambient temps of upwards 30 degrees plus will stay at approximately 180-190, in town of course it relies strictly on the cooling fans pulling air (Two) to keep it from overheating, and it never does, the fans cycle at about 205 to keep it in

the 190 range

Freezing weather without blocking the lower part of the radiator, it stays in the 150ish never really comes out of warm up fueling and so not even want to think about piston ring seal. Sitting in traffic will slowly creep up but once moving will drap quickly during forward speeds. Thinking about this. being a large High-power engine in a small package would require a larger radiator but no place to fit it.

Having the thermostat open low gets the coolant flowing and starts to stabilize and slowly build heat relying strictly on the small radiator to shed it, it seems like they had to pick the proprietary of the two exils and that is seasonal riding

I Know I threw a lot above but usually I can work through it, What I do not understand is how it really works in technical, because I about confused myself silly.

Thanks Man! It was great spending time together with you at SEMA, See you at the first bagger race in Daytonal
 
Here's what's in the above email. HTH

Cooling Large displacement motorcycle engines

Sent: Monday, January 22, 2004 10:00 AM

Tec jeff Celentano

Subject: Re: Large displacement motorcycle engines

Motorcycles use a system modeled like the Rotemp style thermostats that open at a lower water temperature than what we consider normal to help prevent temperature rise By sending the coolant to the radiator early, it starts cooling before the water temperature rises and prevents spikes and boil over and hot pockets. This type of system works in vocations needing a large heat shedding radiator and no place to package it

This has the merit of suppressing overheating by circulating the coolant water to the radiator from the low water temperature, With a warmer thermostat it would never cool proper in warmer climates trapping coolant in the engine block until 190 would lose control of cooling physics, On the other hand, it is known to cause overcooling especially in winter season because it starts circulating when the engine is not sufficiently warmed up if this tendency is noticeable, it may be necessary to take measures such as blocking part of the radiator or using an elevated temperature thermostat during the winter season. Sending you white papers that really explains what we found out years ago on a V-Max and what Porsche found and solved using vortexes in the V-rod cooling systems.

Two Months to go and welcoming warmer Daytonal

Thanks!

Vihaan

From: Jeff Celentano <jce

Sent: Monday, January 21, 2004 9:59 PM

@matorsports.support.mahie.ap

Subject: Large displacement motorcycle engines

HI Vihaan, been pondering this question for months, thought, think, doubt, but you know we tend to overthink and lose the facts that we already know!

The trend with Kawasaki and other brands of large displacing motorcycles is low temperature thermostats, Example my daily 1400 cc thermostat opens at about 144 degrees During warm months no issues the bike out on the highway in ambient temps of upwards 30 degrees plus will stay at approximately 180-190, in town of course it relies strictly on the cooling fans pulling air (Two) to keep it from overheating, and it never does, the fans cycle at about 205 to keep it in

the 190 range

Freezing weather without blocking the lower part of the radiator, it stays in the 150ish never really comes out of warm up fueling and so not even want to think about piston ring seal. Sitting in traffic will slowly creep up but once moving will drap quickly during forward speeds. Thinking about this. being a large High-power engine in a small package would require a larger radiator but no place to fit it.

Having the thermostat open low gets the coolant flowing and starts to stabilize and slowly build heat relying strictly on the small radiator to shed it, it seems like they had to pick the proprietary of the two exils and that is seasonal riding

I Know I threw a lot above but usually I can work through it, What I do not understand is how it really works in technical, because I about confused myself silly.

Thanks Man! It was great spending time together with you at SEMA, See you at the first bagger race in Daytonal
Thank You, Bud- was not aware it was unreadable!
 
What do you use to cover half the radiator? I know this is done on trucks, but they are covered in the front on the grill. On a bike I assume there isn't anyway to attach except on radiator itself. Maybe some pictures too.
 
Using a piece of cardboard cut from a heavy-duty box, Cut it so that it fits snugly across the span.
There are small slots on each side of the middle fairing that the cardboard will drop into right in front of the radiator foam to the plastic fairing.
Height will be your experimenting for your climate, FYI mine ended up at nine inches after trying different heights.

The pictures are a little crude snapped on my way out of the garage to work but gives you the general idea of the area where the cardboard drops in the slot
 

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If you’re using a radiator guard that attaches to the top using zip ties and a single bolt at the lower mount, just sandwich a piece of poster board between the two!
 

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