Cooling issue (cbr600f3)
 

cbr600f3

Having a issue where I put coolant in the radiator and burp the system like normal with the cap off but I’ve got coolant being pushed back out. If I ride hard on the thing the overflow will fill up in less then 5 min and start overflowing. When I’m easy on it I can ride it for a while before it acts up (if it does). It’s not overheating just can’t keep coolant in it.

Don’t believe it’s the head gasket because the oil isn’t milky but idk. Not seeing any other leaks

Anyone come across this issue?

if It was to be the head gasket can I use the 67mm gasket? I’ve heard the 65mm (bore size) but can’t find one for the life of me
Thanks!

Do you recall the temp when it starts to pour out? Coming from a car perspective, it sounds like a faulty Tstat? I only say that because you say if youre hard on it, it happens quicker. My second thought would be a block in the coolant hoses/passages however I have not ran into this issue so I dont have much to offer idk tho

From what I’ve noticed around 200*f but the level will climb faster then the temp will. Might sound stupid but there is no Tstat where it normally would be. Could this be the cause of my issue? The motor has ran like this for years without an issue.

Yeah, need thermostat to keep coolant inside engine. Otherwise, it'll just be pushed around at full-speed.

Yeah, I'd recommend putting in a tstat. A tstat will stay closed until coolant is at temp so if you start your bike and take off, chances are the coolant is still ambient temp which isn't ideal.

And who knows, maybe while putting a tstat in, maybe you'll find something else concerning with a hose or something.