Overheat, coolant explosion and dead fan? HELP!

[Milky]

I hav a zxr l1, had it about a week and i've only ever ridden it on open/faster roads. yesterday i went through town in the sun and traffic. It's never overheated before and the temp guage is usually bang in the middle where it should be or below. So, i was sat in traffic, thought i saw abit of smoke/steam arround me, looked at the guage and it was wayy off the scale. so i pulled over and wached the bike empty all of the green coolant over the exhaust from the reservoir. I took the bike apart when recovery had taken me home and found it'd just been chucking it outta the breathe pipe because it'd got so hot. Then realised that the fan on the left side of the raiator doesnt move at all. So surely this is why it overheated as there was no movement of air around the radiator to cool it down when sitting in traffic?

I topped the coolant back up and the bike's fine but if you sit still on it and rev the bike when it's been run around abit the temp gradually keeps going up, but then as soon as i pull away again and air starts getting to the radiator it goes straight down really fast to where it should be.

When should the fan be running? What could be wrong with it? ( I found the fan disconected above the radiator and re-connected it but this has made no difference! )

Is it bad to mix two colours of coolant together? Or is that just a selling con? haha I had a litre of green left in the bike and i stuck another litre of red in there to fill it back up! Both coolants were the same strength/ratio so surly it shouldnt matter?.. coolant is coolant..

Thanks!, Tom.

[Banditmax]

Fan should come on before it gets to overheating temperatures. Most likely to be a dodgy thermoswitch on the fan, unless the fans knackered. Hook the fan straight up to a battery and see if it spins first.

[billinom8s]

make sure the coolant isn't over filled. Plus make sure all the air is out of the system.

[TLS-Moose]

As banditmax said, jury-rig the fan direct to the battery to see if it works. If it doesn't, get new fan If the fan does work, then look at the thermo-switch (usually also on the radiator). The manual will give test criteria for this

If it's any consolation, I have to have a look at my fan, as I have noticed it's not cutting in ....... but there again it's not usually an issue as my bike generally runs at around 80 degrees C, and the fan doesn't usually cut in until about 98

[Milky]

ok thanks! i'll check out the thermostat then and stick the fan on the battry etc. I'l let ya know what happens. Cheers, Tom.

[Milky]

I mentioned in another post that my radiator brackets have snapped at the top. The movement of the radiator caused the wiring to the fan to come apart and therfore the fan didnt kick in when the bike got hot! I've moved the re-connected wires now and the fan works and the bike now stays cool

If it interests anyone there's a few pics below of what caused it etc.. Cheers, Tom.

Snapped brackets from previous owner's crash..



Wiring pulled apart.. (Back together in pic)





Breathe pipe where it was all pis.sin out from. You can see where it was all steaming off the exhaust..