zxr400h overheating

[fence post]

hey guys

bikes been overheating recently...ive checked the thermostat,water pump,hoses,water levels,air filter,spark plugs...cant think of anything else.
i mostly use the bike for out of town rides and maybe 3 times a week in the city..its fine on the open road for about 20mins then the temp starts climbing as my revs start climbing,riding faster doesnt really cool it down just holds it constant untill i start slowing.fan is manual so its working fine.bike goes for maybe an 1hr in stop start trafic taking it easy before slowly heating up and thats with the fan on.the overflow resivour fills up with coolant then spits out the breather hose...im stumped....any help/advice greatly appreciated!!

cheers

[Karma]

Blocked radiator? Maybe need a flushing?

[Boosted]

make sure the oil level isn't over the limit either...

[slimjim]

reckon you should take it in too a shop, as thee rule if it's starting to boil, is air is been drawn into system and this should not be happening, as the cooling system is gerenally air tight and will release pressure through the rad cap,however your's sound's like it's drawing air in and expanding the water pressure out into overfill tank,some times this is caused due to a crack opening up under heat and opareting temp, so it will pay to get a shop to have a look, they can do a pressure test and if there's a loss, then they can trace it , all the best anyway, let us know how you get on

[wtf?]

yep, i reckon slimjims on to it. either air is being sucked in or there is still air trapped in there from when the coolant was last replaced. dirty coolant or residue in the overflow bottle can mean blown head gasket or cracked head.

[fence post]

thanks for all the quick responses guys!!!
slim jim,i think ur right,i was hoping not to take it to the shop but i guess theres no other choice....
let u all know how it goes....cheers!!!

[FROSTY:Me]

Its interesting that the H model has the SMALLEST radiator of all the zxr's
mella yella used to get pretty darn hot sitting in the pits--I fitted a rad off an L model and the problem went away
Might also pay to check how much anti freeze is in the system

[steved]

Symptoms sound similar to a blown head-gasket. Pray that it isn't that.

[MVnut]

Sure sounds like a head gasket. Good luck.

[fence post]

its cofirmed...head gasket!!!
and of course no shop in n.z hav one in stock...3weeks frm japan...but found an auzzie site that stocks them nz$68 posted in 5 days...cant wait till it arrives!!!
damn gasket made me lose my ride at the KB track day on sunday,but still went and passed it on to me mate on the only ducati there...awsome day frosty!!!!hope she runs fine by the next KB track day!!!

[steved]

its cofirmed...head gasket!!!
and of course no shop in n.z hav one in stock...3weeks frm japan...but found an auzzie site that stocks them nz$68 posted in 5 days...cant wait till it arrives!!!
damn gasket made me lose my ride at the KB track day on sunday,but still went and passed it on to me mate on the only ducati there...awsome day frosty!!!!hope she runs fine by the next KB track day!!!

Are you going to do the work yourself?

[slimjim]

sorry to hear that its the top, however good that no other damage done, great to know that you posted what you found ,cheer's , as steved has asked , you doing the work?

[fence post]

na,anything inside an engine scares the shit out of me!!! i dont wana stuff any timing or what not...dont mind swapping engines and stuff but opening them?????i'd love to learn though.
i blew the old motor 2 months ago...con-rod pulled frm piston and put crack 5mm wide 5cm long at the back cracking the starter mtr off bracket then proceded to the front and went threw block making hole the size of a plum and continuing down to the sump before snapping and sitting in my fairing.
good times!!!