zx6r 08 overheating???

[Kleinelars1.]

Hi Guys,

I'm Lars, from the Netherlands and as I'm having a similar problem with my zx6r 07/08 i'm hoping someone here can help me out.

Last year i bought this bike for track use. Unfortunately a few track days ago I noticed that the fan wouldn't power on. So I by-passed the sensor and made a switch that I can power on/off myself.

But, even with the fan on during the 20 minutes on track it still runs 224-226 degrees (106-108 degrees celcius) with a weather temperature around 68 (20 degrees celsius).
I even noticed the temperature running up to 241 degrees (116 celsius) on a verry warm day with 90 degrees (32 celsius) although I kept the fan running from the start.

So what did I check untill now:
-Thermostat--> it nicely opens full 8mm around 180 degrees.
-Radiator--> warms up everywhere, no cold parts so it is ok
-Flushed the system with a radiator cleaner, after that with water.
-Filled it up with demi-water and added 5% Motul Mocool which should lover the temperature with about 5-10 degrees.

After this the engine still runs to 224-226!!

Sow do you have any other ideas what the problem might be??

Thanks a lot!

[stoinkythepig]

A failed head gasket would be my guess. If you know someone with an exhaust gas analyzer, have them put the probe into the coolant overflow tank while the engine is running. If they can measure any carbon monoxide, the head gasket is probably leaking combustion gasses into the coolant.

[Jim]

i dont run a radiator fan on my race bike. temps usually run 200-210 F when i roll back in the garages.