ZZR 250 OVERHEATING AND POSSIBLE ENGINE DAMAGE

[desertdance]

Coming back from work the other day, i got home, parked my bike in the shed, the old man comes over and says, gee it smells a bit hot, seeing as I had just come back from 10 hours of work in a saw mill I wasnt really interested in what he had to say.
A couple days later on my next ride I noticed that it was very doughy below 8,000 rpm, although as soon as it got above 8,000 the power would pick up and it would rev through cleanly (8,000-12,500). On the return trip the power was doughy the whole way through the rev range. I got back parked the bike in the shed and realised there was steam coming from the radiator, and coolant leaking out, we checked the coolant reservoir to find that 90% of the coolant had leaked out. We got a bottle of radiator stop-leak, followed the directions accordingly, rode it around for 20 minutes while the stop leak was supposed to work its magic. After a 20 minute ride i had coolant leaking from the water pump, i know that im up for a new water pump. Has the leaking radiator and lack of coolant damaged my engine (the aforementioned "doughiness"), I had ridden for about 30km's with the doughiness throughout the whole rev range.

[seiko1]

Maybe the thermostat is stuck shut!
Sounds like you have excess pressure there.
Hot engines are pretty gutless anyway but I doubt it is damaged if it's still going
Oh and welcome to KSRC
(to test thermo, just put it in a saucepan and bring to boil....see if it pops open)

[mike-s]

If your really concerned run a compression test, you'll know quick smart if its holding compression or not.

[swearbear9r]

hi and welcome mate .............. and yer wot they said lol

[desertdance]

Thanks for the advice, fellas. It has now been resolved with a replacement water pump and radiator. Seems like the problem started with a faulty fan switch! I didn't think that the system was soo dependant on the temp remaining within a very narrow range for optimal operation.Seem like it is .
More fragile than an air cooled system.Thanks again

[mikk]

yeah... engine will be ok. i heard that oil does more than half the cooling in these so i think it will be fine if the temperature gauge wasn't going crazy

[tim]

good news she's fine, must have been a scary few days...

[ZZR250-PT]

Noticed one day my fan was going overdrive mode... Turns out the Coolant system had a leak somewhere so for new riders having the fan come on more then usual would be a good indicator that something's up.

[RyBoy]

Hi All,
I had to replace my fan switch, Temp sensor and thermostat in my bike this week, though picked them all up for $30, and its simple as hell to do!
And I am new to this motorbike game!
Now I have a temp gauge that works, though I need to wait until the gasket goo dries before I can see if the fan switch works,
But WIN!