Hi, have 04 bird, recently developed a losing coolant issue, is only via overflow after a run, temp reading on dash is 100c - 103 in traffic but back down to 84 - 90 when doing 80+ km fan kicks in at 100 every time, when I stop and switch off I can here i gurgling back into reserve tank, I did top it up last time may have overfilled to cause this mornings event, but curious to know how accurate is the temp reading on the dash, can it overheat and reading does not register correclty, has got me a bit baffled

Any help really appreciated, I am heading to drags tonight I dont want to get pulled off start line due to dropping coolant on the track

Thanks Grant

Go get a rad cap,almost anything(from any bike) will fit,I think (and this is totally without checking) 13lbs is stock,couple more won't hurt.That is the most likely culprit.As safety measure zip tie a catch can to the overflow line if you can.The temp guage is most like fine,they generally work or don't work in which case its almost always the sensors fault not the actual guage.

Thanks Al, def coming from overflow, think (hoping) just overfull - but off to drags now, no rain in site but dam hot & humid here, x fingers street series tonight, got to get past round one

Well issue is still there, got to drags, she dropped another puddle of coolant just below overflow - temp was fine reading 100, dropped to 84 - 90 on highway, parked and switched off piddled all over the ground, did not do it again all night or when I got home, temp seemed to stay normal on the gauge,

any other clues appreciated, is it likely thermostat is failing - but I would think if it was staying closed it would over heat - staying open what would that cause?

Sounds like you might have overfilled the resevoir it should settle down in the overfill bottle,you cant keep on loosing fluid,if your thermostat stays open your temp should be cooler,if failed and stays closed you should overheat

Originally Posted by bullit

Sounds like you might have overfilled the resevoir it should settle down in the overfill bottle,you cant keep on loosing fluid,if your thermostat stays open your temp should be cooler,if failed and stays closed you should overheat

Thanks heaps good to get 2nd opinions, that was my theory, but it has dropped its guts 3 times now, thought it should be at correct level by now,

The symptoms you describe happen when there is a pressure loss in the system-most often caused by a faulty rad cap-I have had this happen and it was exactly as you describe word for word.I don't know if air in the system can cause this,fairly sure it can't.Thermostat-can't see that,when they fail its usually failing to open causing overheating-you're running temp is fine,if it was stuck open you would first notice it taking longer to warm up,and its relatively rare.
Like I said,most rad caps are the same fit from what I've seen,borrow one for a test.

Rad Cap - agree fully with what Partsguy has been saying.

Theoretically a large stationary air lock could cause this to happen ...... if more heat was added (i.e. heat soak) the air would expand increasing the pressure in the system but if that could cause enough pressure rise to lift the seal in the cap who knows.

New cap, blead the system well and don't overfill the expansion tank, run up to temp a couple of times (to where the fan comes on) and allow to cool, check the expansion tank (I have had to remove some coolant after a change once) after each run and my gut feeling is that the problem will be a thing of the past.

OK, thanks Al & duck, makes perfect sense now,(when explained why rad cap would cause this) definitely air in system when warm get a glug noise when off, air escaping into expansion tank, most likely, should have listened to you first time, will grab new cap during the week give it a flush etc

Thanks heaps,

OK top marks go to Al - Parstguy - radiator cap was the problem, replaced with new genuine item, had a 200k ride today, not 1 drop of coolant lost, thanks Al, I will listen next time you suggest a solution.

Originally Posted by grantxx

thanks Al, I will listen next time you suggest a solution.

That line is equally true of others here on the forum notably GrahamCuk and The Duck, IMHO not listening to any of these guys can be detrimental to bike and health.. I may debate with them from time to time but i do so in the interest of learning from thier experience...

Thanks Grant,always good to know I'm still useful.
I'm definately not always right,but I try.

I like noticing the difference between guys like me,let's say the "all business straight to the shortest answer" types and the mechanical engineer types of Duck & Graham.You get the FULL reason why with those guys,you get the either been there done that answer or my best logical guess based on experience with me.

Too much reading for me the other way.

Originally Posted by Partsguy

Thanks Grant,always good to know I'm still useful.
I'm definately not always right,but I try.

I like noticing the difference between guys like me,let's say the "all business straight to the shortest answer" types and the mechanical engineer types of Duck & Graham.You get the FULL reason why with those guys,you get the either been there done that answer or my best logical guess based on experience with me.

Too much reading for me the other way.

Strewth you don't half go on Al, sorted Grant

[

QUOTE=TheDuck;248289]Strewth you don't half go on Al, sorted Grant

Who me?
BTW,that's the second time I've had to look up "strewth".
I liked this Australian-English Dictionary - Uncyclopedia, the content-free encyclopedia