Hayabusa overheating?

[arctic954]

So.... I have a 2002 Hayabusa ----

Just put the bike back to 100% stock.... when the bike had the full hindle system & power commander --- not once did the bike's temp gauge ever creep up past the center position.

So, now the bike is running just off the stock ECU and stock exhaust w/ stock air filter.

The other day --- sitting in traffic, while idling --- the bike starts to rise past center --- hits the red mark...the fan kicks in.... at which point I was on the highway and started getting air to the radiators --- and she cooled off....

So --- decided to do some testing today to make sure I'm just not paranoid.....


Had the bike up on the stands --- with a fan pointed towards the radiator.....also pulled the plastic to make sure all the throttle bodies vacuum hoses were connected and that the throttle body boots all had a good seal --- everything looked great.

Bike didn't overheat while idling with the fan on it...... I then pulled the fan.....bike after 2 minutes started to creep towards hot....

Fan doesn't kick on until right before the red mark on the gauge....

I then turned the fan back on..... needle creeps back towards normal.



So ---- first question..... does the fan only kick on --- right before the red mark on the gauge? is this right?

2 ---- I'm thinking the thermostat is o.k.... because if it was stuck closed.... wouldn't it not circulate coolant and thus not cool down EVEN with the fan running?

Any other thoughts?

or an I just being paranoid and this is a normal thing when running the stock exhaust?

[dadofthree]

Might be normal for the Gen I. They don't like heavy traffic. You'll get all kinds of opinions. There's a fan mod and a fan mod that adds a second fan for the Gen I. The Gen II comes with two fans.

[Schism]

i could be wrong but i recall that the fan kicked on right around the half way mark or just a hair below. my guess would be the $20 thermostat which is very easy to change or she needs a burp from the air in the system. i not 100% sure but i believe the fan is triggered when the thermo reaches a certain temp. why not try both to rule things out for you?

[GoldenChild]

perfectly normal when idling..quit stopping,lol..

[arctic954]

yeah --- figured....... Funny, coming from the guy that bought my full system! (which is in the USPS mail w/ insurance BTW)


My TL1000R was nictorious for doing that.....

But -- the thing that messed with my head --- was that with the full system....it NEVER went above center.... 90 degrees, idling for 20-30 minutes.... no prob.

[The Big Red One]

So.... I have a 2002 Hayabusa ----

Just put the bike back to 100% stock.... when the bike had the full hindle system & power commander --- not once did the bike's temp gauge ever creep up past the center position.

So, now the bike is running just off the stock ECU and stock exhaust w/ stock air filter.

The other day --- sitting in traffic, while idling --- the bike starts to rise past center --- hits the red mark...the fan kicks in.... at which point I was on the highway and started getting air to the radiators --- and she cooled off....

So --- decided to do some testing today to make sure I'm just not paranoid.....


Had the bike up on the stands --- with a fan pointed towards the radiator.....also pulled the plastic to make sure all the throttle bodies vacuum hoses were connected and that the throttle body boots all had a good seal --- everything looked great.

Bike didn't overheat while idling with the fan on it...... I then pulled the fan.....bike after 2 minutes started to creep towards hot....

Fan doesn't kick on until right before the red mark on the gauge....

I then turned the fan back on..... needle creeps back towards normal.



So ---- first question..... does the fan only kick on --- right before the red mark on the gauge? is this right?

2 ---- I'm thinking the thermostat is o.k.... because if it was stuck closed.... wouldn't it not circulate coolant and thus not cool down EVEN with the fan running?

Any other thoughts?

or an I just being paranoid and this is a normal thing when running the stock exhaust?

Sounds like maybe a bad temp sensor unit. Fan should come on way before the red....somethings not right. Considering the age it might be time for some cooling system maintainence and sensor checking. A full system will def help the bike run cooler, but it sounds like it was only masking a developing problem
On a side note...my bone stock first gen NEVER went more than a needles worth over halfway sitting in 30+ minutes of road construction/traffic jams/wrecks etc in mid-upper 90 degree temps. They will run like a car if working properly and maintained right. I've owned a ton of bikes and never had one handle heat as well as the bus
There's some things about my busa I don't like....but reliability and heat handling aint 2 of them

[arctic954]

yeah --- I agree.... I think the full system and rich map was masking a developing problem.

I would expect the fan to kick on way sooner.....


Looks like I need to start going through the list.....

1. Burp system
2. Double check the radiator cap for proper function
3. Do an electrical test of the temp. sensor....
4. Swap out the thermostat

[arctic954]

hum.....

I need to go home and dig into my Clymer now....you all have me thinking...

[marc1996]

You have a bad temp sensor. The fan should kick on just over the half way mark on the gauge. If yours is coming on right at the red, either your temp sensor is faulty and/or the thermostat sticking closed. My .02 change both

[mike1180]

Yep the fan should come on just a little past 1/2 way on the temp gauge.

[arctic954]

ah......I just figured it out.....

The busa has a engine coolant temperature sensor at the back left of the engine..... this sensor is resistance based and directly controls the coolant temperature guage on the guage cluster.... figured out you can actually turn the bike on....unplug the sensor and change the guage needle by varying the resistance.....

The trick being......the fan is not connected to this....its way simpler....

On the left side of the radiator is a THERMOSWITCH...... which is not conected to the guage....but controls the fan seperately....this sensor simply turns the fan on at a certain temperature.... figured out you can turn on the bike....disconnect this sensor....short the unpluged connector and turn on the fan......

so....... basically my only problem is a bad THERMOSWITCH.... the fan simply isnt turning on at the right time....

Figured out that the thermostat is o.k and not stuck closed because if it was stuck closed.....turning a fan towards the bike would not cool down the bike......because coolant wouldnt be circulating correctly.....

Thanks everybody.....you all got me in the right direction....
Posted via Mobile Device

[The Big Red One]

[Austin007]

On a side note...my bone stock first gen NEVER went more than a needles worth over halfway sitting in 30+ minutes of road construction/traffic jams/wrecks etc in mid-upper 90 degree temps. They will run like a car if working properly and maintained right. I've owned a ton of bikes and never had one handle heat as well as the bus
There's some things about my busa I don't like....but reliability and heat handling aint 2 of them

I would love to know how your bike could do that, and make mine do the same. I hate that my 03 heats up so quick in traffic. I just cleaned the coolant overflow tank gunk out, and refilled the whole system with fresh premixed antifreeze, no additives. It's still on the original thermostat, after 55,000 km (34000miles). Do you guys think a t-stat could cause this? It's never been that good in hot weather when driving in first gear in the city. Any good tips on changing the stat myself?

[mrnyc01]

I would love to know how your bike could do that, and make mine do the same. I hate that my 03 heats up so quick in traffic. I just cleaned the coolant overflow tank gunk out, and refilled the whole system with fresh premixed antifreeze, no additives. It's still on the original thermostat, after 55,000 km (34000miles). Do you guys think a t-stat could cause this? It's never been that good in hot weather when driving in first gear in the city. Any good tips on changing the stat myself?

Bump.. I want to know myself....

[Austin007]

no more info from the guy i guess.

[mrriverajr]

My 2006 Busa is doing the same thing all of a sudden. Now I am paranoid so I just ordered the lower fan switch (180) and a new thermostat I will also change out all the fluids. I will keep you posted on my progress once the parts arrive.
If you guys have fixed your issue please let me know!!!

Thanks

no more info from the guy i guess.

[lisma]

Hi I think most of 1st GEN always overheat when in a jammed road. Mind also the same but when start mving it getting colder...but only in the traffic light she will raise again the temp... tension

[mrriverajr]

Fan Switch override installed, T-stat, lower temp fan switch and engine ice all complete

My 2006 Busa is doing the same thing all of a sudden. Now I am paranoid so I just ordered the lower fan switch (180) and a new thermostat I will also change out all the fluids. I will keep you posted on my progress once the parts arrive.
If you guys have fixed your issue please let me know!!!

Thanks

[dadofthree]

[Dennis L]

Dont Gen 3 come with 2 fans? the 1340cc Busa? My '07 does the same thing replaced coolant test temp switch/t-stat all ok.