operating temp?

[ironman]

Hey everyone, relatively new to the forum. I joined back a couple months ago but have mostly been reading and learning from the discussion. First post.

My question is for all who ride '07 or newer fizzers. On the digital display, there is a temperature reading that can be swiched between the intake temp and the engine coolant temp. The engine coolant temp being an estimation of engine temp. It is my assumption that this reading is very similar to the engine temp reading that we have in our cars. However, I notice that when I ride in warmer weather (say 80 F or so) then the average coolant temp runs between 185 and 205 depending on pace and stoppages. But in cooler weather like today (mid 30s F) the coolant temp after warming up thoroughly and riding for 20-30 mins is averaging 158-170. I understand that according to the manual this is permissable for continuing to ride, but seems to be a considerably greater fluctuation than most cars. My understanding of how a thermostat works is that a coil mounted valve opens and closes with temperature to increase or decrease flow through the radiator thus decreasing or increasing engine temp respectively. So, it seems that either the range of acceptable operating temp is very broad, or my thermostat is not working correctly, or the coolant temp is measured as it leaves the radiator instead of as it leaves the engine compartment.

I suppose my question is. . .
1. Does everyone else have this same fluctuation and I am needlessly concerned that my thermostat isn't quite working right?
2. If that great of a fluctuation in operating temp occurs on all the bikes, then isn't it going to adversely affect the fuel economy when operating the bike at lower temp ranges?

glad to be a part of the forum,
-Luke

 

[Norm]

I'm pretty new myself but the members here have taught me a ton. I'm also the furthest thing from a mechanic. In fact, reading your post, you're like Albert Einstein next to me. But your readings are very much like mine, and most everyone else here. One thing I've learned about most bikes, unless we're talking about BMW's or the Honda Gold Wing, they're just so much less forgiving and less sophisticated than our cars. In fact 3 members here simply had a pebble land in their cooling fan, which then quickly burnt out the fan motor.

My temps fly up quickly to 210 F on a hot summer day just sitting at a traffic light for a couple of minutes. The fan comes on at that temp and will run till the temp gets back down to below 200F. Even while moving the temps are about 180 F in the summer. Now, in the cold, my temps are down about 160-170F.

 

[Ghost Weim]

Yup - my '07 fluctuates in those temp ranges as well.

The other day I was riding in some pretty cold weather and when I first started out didn't even get an actual reading.

 

[ant_mb]

On a cold day it's hard to get it to 170 while moving, it usually runds 165 or so. If it's a hot day it will stay about 180-190 while moving and 200-210 while sitting. Your bike is working correctly.

 

[ptastuart]

Same here..

 

[wrightme43]

Yep not a big deal man.

 

[mellofelow]

Yup... I get the same variation. I read the temp constantly, almost as often as speed & tach, probably more than fuel gauge.

And what's up with the switch to intake temp? what a useless feature. it should have been ambient temp reading.

 

[Norm]

And what's up with the switch to intake temp? what a useless feature. it should have been ambient temp reading.

I'm with you on this for sure. Would much rather have ambient temp like I've had on other bikes. It's been pointed out on this forum that the intake temp can be done with the same device and the ambient temp requires a whole separate device but still I don't know how to use intake temp.

 

[SovietRobot]

How do you get oil/engine temp? All it'll display for me is intake temp, which is always like 83F even when I'm at 4-5 bars

 

[fz6gow]

I have the same question as SovietRobot, I can't seem to get it to display anything other than the intake temperature. Is that something they started putting on the 07's?

 

[madmanmaigret]

I have the same question as SovietRobot, I can't seem to get it to display anything other than the intake temperature. Is that something they started putting on the 07's?

I can't speak for the '06's and under but on the '07 and up you just push the "reset" button once and it switches between the 2 readings.

 

[Fred]

That makes the FZ6 unique is not the fact that the temperature fluctuates like this, but the fact that it has a gauge which lets you see it happening.

Every water cooled engine made will behave this way, getting hotter at times and colder at other time.

But the temperature varying all over the place like this tends to make people nervous (as evidenced by the number of posts to this forum asking about this phenomenon) so the average temperature gauge is designed to respond very slowly to changes in temperature. The temperature is still changing in the engine, but the driver no longer sees it happening.

As others have said, it's perfectly normal.

 

[druk]

The described behaviour is "normal" in the sense that it happens to all of us FZ6 users, but it certainly doesn't SEEM normal when compared to the theory of the cooling system (water/radiator/pump/thermostat/fan) or to the practice of cars.

In cars with their cooling systems in good shape, the needle reaches the operating temperature and then stays nearly still. It doesn't matter if it's summer or winter, or if you are in the middle of traffic or on the highway at 3.00 AM: the needle is like stuck. It's the magic of the thermostat.

But the behaviour exhibited by our FZ6s is the same as cars whose thermostats have been removed. Except for one thing: the FZ6 gets warm very quickly, while a car without a thermostat takes forever to reach operating temperature, or may never reach it if it's cold and you are on the highway with no traffic.

So the question remains: what is the temp gauge measuring? Is there really a thermostat in our FZ6s? Or perhaps just an electric pump which is turned on and off depending on the temp readings?

 

[Jblk9695]

I have the same question as SovietRobot, I can't seem to get it to display anything other than the intake temperature. Is that something they started putting on the 07's?

I have an 09 and you have to turn the key to on(don't start the engine) and push the reset button to access the intake temp. After you start and then shut down and turn the ignition off it defaults back to engine temp. So you may try the key on and push the reset to see if it goes back to engine temp.

Jerry

 

[RJ2112]

The temp variation is bigger than on a car motor, because the motor is much less massive (not as big of a thermal sink).... because it can also get a lot hotter due to it's state of tune (at one liter, it would make about 150 HP stock.... or equal to 300 HP with a 2 liter motor), it needs a relatively large radiator to shed the max heat in max power mode @ max ambient temp.

When the thermostat opens, there's a lot more raditor available to the coolant..... colder air cools it faster than would happen with a smaller radiator which would more closely match what happens with a car.

 

[wolfc70]

The reason most modern cars temp gauges do not fluctuate is do to a "dead band" in the gauge. What this means is that the gauge will stay at one point for a temperature variance. Take my car as an example, the normal gauge position is 1/3 or half way between the 1/4 and 1/2 marks. This spot on the gauge (according to the FSM) is for 167F-214F. So even though the coolant temp may be changing as the thermostat opens and closes, the gauge never indicates it. Some vehicles have "idiot gauges", or basically the gauge gives no meaning, other than an extreme. Ford does this with there oil pressure gauges, if you have oil pressure the gauge reads in the middle, when you have no oil pressure, the gauge reads L. If the gauge has vague and indifferent markings (H-L, H-C vs actual numbers), take its reading with a grain of salt.

Now on the FZ6, the temp display ('07 and newer) shows what is actually happening, and is not a form of idiot gauge. So the temp swings are perfectly normal. The cycling of temps is just the way mechanical thermostats work. Unless you have a real high or low reading, I would not worry.

 

[Kriswithak]

I notice mine jumps around alot but follows a very logical system:
In extreme cold at speed it doesn't reach the same high temperatures
In heat with slow speeds or heavy traffic is reaches the high temperatures and the fan comes on and drastically lowers the temperature.
Everything in between follows the same kind of logic, depending on the weather and road conditions and whether the bikes fan is on.

 

[druk]

I'm sorry, but I still have some doubts. A thermostat is not an on/off device, it opens and closes progressively. Thus, water temperature should be practically constant once it reaches operating temp (i.e. thermostat starts to open), except when the thermostat is fully open and the cooling capacity of the radiator is exceeded (because it's too hot outside and/or you are travelling at low speed or stuck in traffic), in which case the fan should start.

What I see in my bike is HUGE variations in operating temperature (as low as 72 and as high as 96 celsius after peaking at 103 and the fan lowering it), which in my opinion makes the term "operating temperature" kind of meaningless.

The bike works fine, but this just makes me curious.

 

[Boneman]

I'm sorry, but I still have some doubts. A thermostat is not an on/off device, it opens and closes progressively. Thus, water temperature should be practically constant once it reaches operating temp (i.e. thermostat starts to open), except when the thermostat is fully open and the cooling capacity of the radiator is exceeded (because it's too hot outside and/or you are travelling at low speed or stuck in traffic), in which case the fan should start.

I have to disagree with this stament about thermostats. Automotive thermostats are pretty much on/off devices and are either OPEN or CLOSED. It will 'pop' open when the thermostats operating tempature is reached, not gradually open.

If you ever have the chance to test one, a thermostat is an amazing thing to watch because what they do seems impossible. You can put one in a pot of boiling water on the stove. As it heats up, its valve opens about an inch, apparently by magic! The secret of the thermostat lies in the small cylinder located on the engine-side of the device. This cylinder is filled with a wax that begins to melt at perhaps 180 degrees F (different thermostats open at different temperatures, but 180 F/82 C is a common temperature). A rod connected to the valve presses into this wax. When the wax melts, it expands significantly and pushes the rod out of the cylinder, opening the valve

Usually there is only around a 5 deg temp difference between opened and closed. So even if it dosen't 'pop' open immediately, it will be fully open in a matter of seconds.

 

[druk]

I have to disagree with this stament about thermostats. Automotive thermostats are pretty much on/off devices and are either OPEN or CLOSED. It will 'pop' open when the thermostats operating tempature is reached, not gradually open.

Usually there is only around a 5 deg temp difference between opened and closed. So even if it dosen't 'pop' open immediately, it will be fully open in a matter of seconds.

I'm sorry that you "have" to disagree, , but I'm pretty sure that an automotive thermostat opens and closes gradually. Check out this wikipedia article (the part about Wax Pellet thermostats): Thermostat - Wikipedia, the free encyclopedia

I will copy the pertinent paragraphs for those of you who don't want to bother navigating to wikipedia:

"While the thermostat is closed, the flow of coolant in the loop is greatly slowed, allowing coolant surrounding the combustion chambers to warm up rapidly. The thermostat stays closed until the coolant temperature reaches the nominal thermostat opening temperature. The thermostat then _progressively opens_ as the coolant temperature increases to the optimum operating temperature, increasing the coolant flow to the radiator. Once the optimum operating temperature is reached, the thermostat _progressively increases or decreases_ its opening in response to temperature changes, _dynamically balancing_ the coolant recirculation flow and coolant flow to the radiator to maintain the engine temperature in the optimum range as engine heat output, vehicle speed, and outside ambient temperature change. If the load on the engine increases, increasing the heat input to the cooling system, or the vehicle speed decreases or air temperature increases, decreasing the radiator heat output, the thermostat will _open further_ to increase the flow of coolant to the radiator, preventing the engine from overheating. If the conditions reverse, the thermostat will _reduce its opening_ to maintain the coolant temperature.

Under normal operating conditions the thermostat is open to about half of its stroke travel, so that it can _open further or reduce its opening_ to react to changes in operating conditions. A correctly designed thermostat will never be fully open or fully closed while the engine is operating normally, or overheating or overcooling would occur. For instance,

If more cooling is required, e.g., in response to an increase in engine heat output which causes the coolant temperature to rise, the thermostat will increase its opening to allow more coolant to flow through the radiator and increase engine cooling. If the thermostat were already fully open, then it would not be able to increase the flow of coolant to the radiator, hence there would be no more cooling capacity available, and the increase in heat output by the engine would result in overheating.
If less cooling is required, e.g., in response to decrease in ambient temperature which causes the coolant temperature to fall, the thermostat will decrease its opening to restrict the coolant flow through the radiator and reduce engine cooling. If the thermostat were already fully closed, then it would not be able to reduce cooling in response to the fall in coolant temperature, and the engine temperature would fall below the optimum operating range."