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Discussion Starter #1
I've been riding the bike on some really cold mornings, between 28 and 40 degrees and I've noticed that the coolant temp never gets anywhere near normal operating temp like it should.

I like to see at least 160 degrees and most modern engines have a 180 to 190 degree thermostat. When it is 28 degrees out the coolant temp stays at or below 130 degrees, no matter how long I ride it. This is at highway speeds. As air temp warms up, so does the coolant temp.

Has anyone else seen this on their bike, it can't be normal and it's really bad for an engine to never reach high enough temperature to cook out the water and acids produced by combustion.

I'm going to pull the thermostat and test it this week. I will post up my findings.
 

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I have running temps at about the 140s but its been in the 30s. Gets up to about 170s after a few stoplights, but goes back down once on the highway.

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Discussion Starter #3
That sounds the same as what mine is doing. Thanks for that info. Maybe some kind of design flaw in the cooling system. I haven't looked closely at how the system works, it's set up a bit differently from other bikes. Every other liquid cooled bike or car/truck I've had keeps temps steady even in extreme cold.
 

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I think it is operating normally.30 degrees warmer and you would see a corresponding 165 degrees.
At hi way speeds and those temps I would not expect the thermostat to correct it.
Out of the airstream,yes.
 

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Discussion Starter #5
I don't know the temperature of the thermostat in the bike. If it has a 180 degree thermostat for example, it should stay completely closed until 180 degrees, effectively no hot coolant passing through the radiator. If operating normally, coolant temp should never drop more than a few degrees below 180.
 

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160F, my FZ6R was the same in cold temps. I can see the thermostat open at 160 then the water temp go down a bit when it open and climb up again. I agree 160 is a bit cold. The 09 in general run a bit cold compare to my 6R who was in the 190 to 200 all the time. Could always use rad blocker to limit the cooling effect.

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Discussion Starter #8
There is a small hose that I believe comes out the back of the cylinder head and goes to the right side of the radiator, probably just to let air escape when filling the system. Maybe it is flowing too much coolant to the radiator, bypassing the thermostat when it is closed.
 

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Funny thing is with a digital readout everyone is looking at numbers.
If it was a segmented or dial gauge no big deal but now everone is seeing a number thus all the speculation.
Reminds me of the 1985 GPZ 900,when it came out everyone was complaining that it was running hot because the gauge would
run in the 60% range.
Guess what Kawaski did to fix that; they ran an inline resistor so it would read lower and presto no more complaints. :D
 

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on my way home from the dealer it was 85 degrees and I am on the freeway stop and go. The temp on the gage went to 223. It was too noisy to hear if the fan was on but I think it was. It cooled down once I got up to 20mph. Hard not to worry about it but it only had 45 miles on it then. We get hot summers like 105 and I ride to about 95 or so and I am hoping this will not be a hot running bike. I like the fact it actually has a water cooled oil cooler sitting next to the oil filter.
 

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Discussion Starter #13
My fan came on just past 220 degrees, about normal for liquid cooled bikes, but seemed to take a long time to bring the temp down, compared to others I have had.
 

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My fan came on just past 220 degrees, about normal for liquid cooled bikes, but seemed to take a long time to bring the temp down, compared to others I have had.

If anyone makes a change so it comes on sooner will get my money. Might have to put a manual switch on it with an led to show when it is on.
 

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Discussion Starter #15
220 is pretty safe as long as the fan is strong enough to keep it under 240 or so under adverse conditions. And the system is maintained properly.
 

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Maybe the 09 thermometer for the dash display is located after the coolant has gone through the radiator and most other vehicles before?
v2Bob may be on to something. Don't have the bike yet so can't look, where is the temp sender location?
 

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Discussion Starter #18 (Edited)
Maybe the 09 thermometer for the dash display is located after the coolant has gone through the radiator and most other vehicles before?
I wondered about that too but I bet it is the same temp sender the FI system uses, if so it would have to sense actual engine temp, for the fueling to be correct. I'm going to check my thermostat and look at how the whole system works. I'll post up something if I see anything interesting.
 

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yup mine does the same thing. On cold mornings it was around 140-150 at higher speeds, but it was more like 50 degrees out for me. I can see it showing even lower when its 30. (brr!) Then sitting in traffic it hits 220 pretty quickly and the fan kicks on. hopefully this has no adverse break-in effects when you punch it with 140 (or less) coolant temp.
 

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Discussion Starter #20
I took a look and took apart my cooling system today(don't tell the warranty police). I drained the coolant and pulled the thermostat housing off. It's the black plastic thing behind the header pipes. I pulled the exhaust to make it easier. What I found was a big disappointment.

The thermostat and housing are a sealed unit, no easy way to test the thermostat. But much worse yet, the thermostat is just rattling around loose in there and not even remotely sealed to the housing. Thermostats always have a rubber or other seal around them, otherwise they can't work. This means that coolant can bypass the thermostat when it needs to be stopped by it. I ran some water into it with my hose and a lot gets by, even without a water pump trying to push it through.

This seems like a serious design or manufacturing defect to me, and I can't think of any way to fix the situation, not being able to open the housing. Not only the coolant but also the oil temperature will be too cold, this is really bad, and can cause a lot of extra wear to the engine. I ride even when it's cold out so I'm not too happy Yamaha screwed this up. I hope after they get enough people noticing this and complaining they will come up with an updated part.

Also, the only temp sensor I can see is right in the head, so it is sensing actual engine/coolant temp.
 
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