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I guess I don't see fault in his statement. A coolant temp of 220F is within the operating range of an engine. A stationary bike is not efficient in dissipating heat so the coolant temperature rises. When a certain temperature is reached, the fan turns on to help facilitate air movement promoting more conduction on the radiator's surface area. As to the shutoff temperature, I've never reached it so I can't attest to its validity or even its existence. Maybe I am missing it though as it has been a long day...
 

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No that the bike shuts off 240 and the optimal temp is 220? I don't think so?
That is true. On a hot day, it's not unusual for my Honda to run about 200 degrees.

My Kawi 636 ran about 215 steady. Never had any problems for 36k hard miles.
 

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No that the bike shuts off 240 and the optimal temp is 220? I don't think so?
If your engine's optimal performance comes at 220 degrees, you'll never get to utilize that unless your at a stop light (then you have nothing to utilize). Air is going to cool the engine down when you're riding the bike hard. His statement makes little sense.
 

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I've seen my 1000 reach 239 at a light. At that point it stabilized and stayed there until I was off. The 600 does run cooler though which is to be expected as there is less fuel combusting.

As far as whether a cooling temp of 220 is an optimum operating point, assuming it isn't autoigniting (knocking), there are benefits and drawbacks of a hotter wall temperature. Some might argue that the heat transfer from the intake valve to the fresh charge will have a noticeable decrease on the volumetric efficiency when the coolant temperature is 220F instead of 180F. It does have an effect and needs to be accounted for but valve temperature is not a measurable quantity and is usually predicted via computer simulation. Fuel is less likely to condense on the wall at 220F coolant temp meaning the mixture will be better mixed equaling better combustion. Whether fuel condensing is an issue at 180F and not 220F is something only Honda engineers would be able to answer as I don't think it will be visible on a typical engine dyno.

On a side note, if you could ensure the coolant temp stayed at 180F, one could argue that the compression ratio could be increased as less heat is transferred to the fresh charge before ignition meaning a higher pressure could be used. Higher compression ratio directly results in more power which is always a good thing...
 

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ive had my 03 hit 251 before, right after i wrecked, checked for oil leaks, then took it around the block to see how it rides, let it idle for a few mins while i grabbed some tools out of the garage and came back a few mins later and the lights on and i see 251 and hit the kill switch lol, glad that bike is gone. i dont think they will shut off till it overheats and something goes wrong.
 

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I liked how he closed the thread and then reopened it after members complained.

Oh ya, one of the reason why cars get lower fuel economy during the winter is because the air is colder causing the volumetric efficiency to increase. Since cars have been closed-loop controlled since the 70's, they add more fuel to allow the catalyst to work, hence the fuel economy goes down. I don't care to join the forum though to explain that...

There are quite a few more here:

http://www.metrompg.com/posts/winter-mpg.htm

None of which have to do with the coolant temperature...
 

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one thing you have to remember is that the engines are aluminum and so are the heads, they can take the heat, but when your light comes on thats not good. aluminum is not as forgiving as cast iron is, you can overheat a cast iron engine a couple times and probable be okay. but an aluminum engine might be okay the first time but i doubt the second time. that just my thoughts, i don't thing the bikes shut down at all for over heat; when it shuts down i think it is because you just cooked the engine and did some internal damage. the only engines i know from the factory that shut down are your diesels in your pickups and larger trucks. correct me if im wrong
 
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