Hayabusa thermostat going up after bike is off

ric_rocha5

ric_rocha5

ric_rocha5

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Hello,

I am a owner of a 99 Hayabusa and I started to notice that the thermostat is going up after bike is off.

Once I turn it off and put it on the side stand the pointer goes all the way up, I have looked in the manual and online but i have found nothing about this.:eek:


if you guys can help that would be amazing !


Many Thanks
 
It wouldn't surprise me if the temp does raise slightly when you first stop as the fan will no longer be running and you've got no air flow to cool a still hot engine.

I wouldn't worry about it to be honest as long as your fan is still coming on when you'd expect it to when riding.
 
tom_e said:
It wouldn't surprise me if the temp does raise slightly when you first stop as the fan will no longer be running and you've got no air flow to cool a still hot engine.

I wouldn't worry about it to be honest as long as your fan is still coming on when you'd expect it to when riding.
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Thanks for the reply, I'm sure that is not overheating, as it also happens when i just turn the bike on in the morning.
 
Worked at a Suzuki dealership for 7 years and never heard of this, might be worth trying a new thermostat. Also clean the connections on the fan as something is not reading right.
 
If you've got a multimeter and a service manual there'll be something in there detailing what the resistance should be on the thermostat/fan switch etc that might help narrow it down.
 
Big air bubble? might be worth taking the rad cap off (when its cold) and giving the pipes a squeeze to move any bubbles around.
 
Mine does that too, the temp rises a bit after I stop. Makes sense, once you turn the engine off, it stops cooling itself... so the only cooling you've is passive cooling. :p
 
IC3 said:
Mine does that too, the temp rises a bit after I stop. Makes sense, once you turn the engine off, it stops cooling itself... so the only cooling you've is passive cooling. :p
Click to expand...

The rapid rise in temperature after an engine has been switched off (and therefore stopped generating any heat) is an effect known as heatsoak. All engines suffer from this to some extent unless they have an electric coolant pump that continues to run after the engine is stopped.

Unfortunately the word 'heatsoak' is widely misused by people when they actually mean something just gets hot (e.g. intercooler etc).

The surprising thing is that the gauge is continuing to register temperature with the ignition off, since the vast majority of temperature gauges are electrically operated this shouldn't normally happen.

Just a thought, you aren't using the kill switch to stop the engine are you? On some bikes (and I think this may include the early Busa) this will cause the temperature to read maximum with the ignition on.
 
My K2.. 2003 Busa does exactly the same thing.

Don't know why but have been told it's fine, the temp gauge goes up into the red as soon as I turn it off.

I can also cook eggs on the frame after a spirited ride☺
 
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All the bikes I have owned when hot the fans will continue to run when engine is stopped and ignition is off must be an old busa thing :p

Hi cyclops12 :)
 
.one. said:
All the bikes I have owned when hot the fans will continue to run when engine is stopped and ignition is off must be an old busa thing :p

Hi cyclops12 :)
Click to expand...

None of mine have, Honda or Yamaha.

Mine rises 20-30f when switched off, the coolant isn't flowing anymore, that's all.
 
Think it's something to do with the ignition, i'm willing to bet if he turns the ignition back on
without starting the bike the needle will start coming down slowly.

Hey there .one. how's it going bud? I'm now a very young grandfather... A lad and the next gen of bikers lol.

Already told the daughter that I'm getting him a bike as soon as he's old enough just like I did :D

She's fine with it as she's always loved going on the bikes, not sure if her mother will agree though☺

He's already got a Hayabusa and Rossi onesie:)
 
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cyclops12 said:
Think it's something to do with the ignition, i'm willing to bet if he turns the ignition back on
without starting the bike the needle will start coming down slowly.

Hey there .one. how's it going bud? I'm now a very young grandfather... A lad and the next gen of bikers lol.

Already told the daughter that I'm getting him a bike as soon as he's old enough just like I did :D

She's fine with it as she's always loved going on the bikes, not sure if her mother will agree though☺

He's already got a Hayabusa and Rossi onesie:)
Click to expand...


Lol I told my girl that if we have a kid I will get one of those mini petrol bike for him.

He will be like this https://www.youtube.com/watch?v=5UBPM07RFHc . LOOL
 
Dogbreath said:
The rapid rise in temperature after an engine has been switched off (and therefore stopped generating any heat) is an effect known as heatsoak. All engines suffer from this to some extent unless they have an electric coolant pump that continues to run after the engine is stopped.

Unfortunately the word 'heatsoak' is widely misused by people when they actually mean something just gets hot (e.g. intercooler etc).

The surprising thing is that the gauge is continuing to register temperature with the ignition off, since the vast majority of temperature gauges are electrically operated this shouldn't normally happen.

Just a thought, you aren't using the kill switch to stop the engine are you? On some bikes (and I think this may include the early Busa) this will cause the temperature to read maximum with the ignition on.
Click to expand...

Hello,

I have made a video to show what is happening.

https://youtu.be/eZ17eLa5-eM

Thanks for the help
 
Does this happen if you turn the ignition on with the engine cold...leave it for 30 secs and then turn it off again?

Could it be that the resting position of the gauge is on that side (for whatever reason)?
 
MowyTone said:
Does this happen if you turn the ignition on with the engine cold...leave it for 30 secs and then turn it off again?

Could it be that the resting position of the gauge is on that side (for whatever reason)?
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Hello,

Yes it does, I dont think is the resting position, because if I put the side stand but do not lean the bike it happens also.
 
Certainly looks like a strange sensor/electrical connection issue.

Have you had any work done recently? Work that would have meant disconnecting or moving electrics/loom.
 
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