??? About Thermostats in Race Bikes. Remove? yay or nay?

I havent done anything to it.
but just sitting in my garage idling it will over heat. 244 degrees...

Water is not going into the radiator from the engine, but the small flow tube that circulates wate around the pistons is flowing water, just not the main hose thats on the "output" side of the thermostat.


Here is the link for the 2008 ZX10R Service Manual (15mb) for anyone who needs it.

 

In the service manual they did mention that if 20% of the fins are bent then it will cause over heating.

I have a few (not many) but plan on using s flat head screw driver to open it up.

I was wondering if they made a sturdier Therm. It seems early for one to go bad. 2008 with 3,200 miles on it.

 

^ you can also test the therm one of two ways:

1. turn the bike on and let it warm up. at a certain temp, it will drop. (ie, on my bike at 177 degs, the temp drops back down to 170 or so and then climbs back up). if it does not drop at all (keep in mind i'm talking about idling or near idling rpm), then your therm is not opening.

2. take your radiator cap off. turn the bike on. the level of water should be all the way to the brim. once the therm opens, you will see the level drop dramatically. if it doesn't drop at all by 200 degs, then your therm isn't working.

 

Q: My bike has a digital temp gauge in the cluster (as I'm sure most modern sportbikes do) but the last bike I raced did not... I'm wondering how accurate the OE gauge is?


Q: At what temp should we start to concern ourselves about over-heating?

 

take the thermostat and drop it into a pan of boiling water and see if it opens.

 

Ahhhh...
i did just that...watched the bikes temp ride...it never drop just climb to warning 244 degrees (just Idling)

I also pulled the cap off the radiator.
It was filled to the neck and once it got over a certain temp it just started to boil out. It never drop down.




All good infor in this thread.....Also i can't remember a race weekend where some hasn't said their bike is running hot.

 

^ sounds like the therm is dead.

 

the manual for my bike (honda cbr600rr) says that 248 degs is overheating... it may not be the same for all bikes, but i'd assume it's pretty close across manufacturers.

 

How about the water pump impellar? I've been out of the loop on the new stuff but this sounds familiar.

Your symptoms sound very similar to the Ducati superbikes we had trouble with other than they overheated much sooner of course.

 

It does not sound like your problem, but, temporary overheating at speed can be caused by a piece of paper or plastic flying into the radiator at speed. Once one comes to a stop, the obstruction may fall away, leaving no trace of the cause of the overheating.

 

hrm... impellar is an interesting suggestion. hadn't thought of that, but it would make sense as a potential culprit as well. thanks RCjohn

 

Do you have your fan still installed? If not did you have a box fan pointed at the bike?

If neither then it'll eventually overhead as it can't shead the heat without some sort of air across the radiator.

 

Trust me, we beat our heads against wall over that one and entire weekend and so did the entire FBF Ducati crew until one finally said it has to the be the impellar since we've checked everything else. Sure enough, it was broke and basically just spinning on the shaft(plastic holding the "key" was cracked IIRC). Actually found 2 broken ones in the spare engines in the semi that weekend.

 

What do you mean?

 

Very true. Sounds like us at Jennings with one of the Suzuki endurance bikes in 03.

 

Man you have to love RonAyer. 08 zx10R Microfiche listed online, parts and price... cheapest place ice seen for OEM stuff.

My dealer is about $60 for therm and gasket and takes a week for delievery 2 pick up.
Ron ayers $39 ship to my door.


when i take the old one out Ill play around with guting it or something and keep it in the tool box incase she over heats while at the track one day in the future....

Plus i can test it in hot water like posted and if bad, ill have the new one handy.

 

I know it has been beat to death but there are two possible problems that can happen with not running a thermostat. Every application is different so by no means am I saying this is 100% of the time.

1: The water will not stay in the radiator long enough to dissipate the heat so it constantly circulates and incrementally builds temp until you overheat. This can also happen with a gutted thermostat.

2: The bike could never reach operating temperature. This can cause unnormal wear on engine bearings, especially cam bearings. This will also effect performance because the ECU is tuned to supply a certain amount of fuel based on "normal operating temperature".

Like I said, this is not always the case, just a couple of things to watch out for. I am sure someone will disagree with me somewhere but I have seen both of these forst hand, as well as bikes running great with no thermostat. Basically, dont remove it and go. Watch it closely for a while to make sure everything looks okay. Good luck.