cooling prob.
 

NEW to the forum how are you all and hope to get some good help here. [/align]hope to make a few new friends.[/align][/align]but iv got a lil pain in my side.

im running a 94 CBR 900rr

the prob. is is that its boiling the water out of the radator into the overflow
and filling that up and then pushing it out there streight to the ground. till its dry.
but temp. gauge is not showing hot till it get dry.
and i pulled both hoses off raid. adn stuck water hose in there to see if it was blocked some how well water flows
water put seems to be pumping water just fine.
and i even put the water hose in one side of the raid. hose and turned it on
and water came out the other end of the other hose off raid.
but the water in the raid seems to boil up and push its way out.
what is some possable things it could be thanks[/align]

[IMG]local://upfiles/29806/AA1CF0CB9CE24A7A891673C2275DD148.jpg[/IMG]

RE: cooling prob.
 

Well, it is possible that your water pump **** to bed. If your not circulating then it will definetely over heat. I though they were meachinical on our bikes so I am curious as to how it could fail, but I would check it anyway. Also, if your electric fan coming on at all, because if the water boils our then it definetely over the temp in which that fan should be actuated. If your temp guage is not reading an over heating condition then that needs to be looked into as well. All I know if my bike can run all day and not go past half the guage. When I cruise it runs at a 1/4 of the guarges sweep. Un you are sitting idling for long periods there is not way ituld be doing what it is doing. Check the pump and try pumping water through the garden hose into oe side and seal that side to see if the other end has water flowing out, could be an internal obstruction? Thats all I can think of, let us know.

RE: cooling prob.
 

This may sound like a stupid question, but are you running a 50/50 coolant/water mix? I just ask because water boils at 212 degrees, even less the higher you go above see level, but the thermostat on the cbr 900rr is a 220 degree thermostat. So if you had just water, it would actually start to boil off before the thermostat even opened up to circulate the fluid between the engine and the radiator. Or it is possible that the thermostat just failed, because the sender for the gauge is in the radiator and not in the block. Either of those would explain the boiling coolant without showing an overheating condition.

RE: cooling prob.
 

water put was working fine seems to me
i took off one of the hoses and started it up
and water shot out pretty good.
and as far as coolant and water mix
it didnt matter so far as far as mix straight water
or full coolant ice.
seems to be doing same.

what if i just took the thermasate out all together
i have done that in past on car eng. and just took a few min. longer to get warmed up
more or less just made it cold natured lil more.
but bike as sits right now starts right up
without choke anyway. even after 2 3 days.
of sitting

56,000 miles seems to me someone rebult it at some point
but all seals and bolts look to be orig.
still
so im gonna check the therm. tomorrow when i wake up.
but how about it out all together

RE: cooling prob.
 

Yeah, I'm going through the same thing. Some good ideas over at the Blackbird page. Think I'm gonna start with checking the cap again and then a flush and fill. Good luck, please post up if you get it solved, I'll do the same.

http://www.cbrxx.com/engine-airbox-e...erheating.html

RE: cooling prob.
 

temp gauge dont get hot at all till its dry but i dont let that happen.

RE: cooling prob.
 

see the whole thing with this and what I was saying before is if the coolant is circulating, then even if your guage is shot, and your fan thermostat is shot, you still should not be overheating like this under normal ridinnditions. I have ridden all summer around town on on the backroads with no major ighway action and my fan has not come on once. WHat I am getting at here is, are you running hotter than you should be. How do your plugs look? Are they white or a light brown? If your plugs are white then you are running lean, which will make the bike run much hotter and eventually cause engine damage. I think that your cooling systme sounds OK, but if I am reewading you post correcly it looks like the bike has 56,000 on the clock. That is high mileage and the only other thing I can think of is that you have excesseive scale and buildup in your coolant passages that are not really allowingefficiaent transfer of the heat from the engine into the coolant. THats all I go for now but your bike should not be overheating like this, fan or no fan, especially if your not idling her all day or sitting in city traffic. Good luck, keep us informed.

RE: cooling prob.
 

ok took therm out today still same thing
took top hose off raid. and put a garden hose in it. let her rip
water flowing all way through back to top of raid. and out.
took the bolt out of waterpump cover out and water flowing out of there.
started it up now water shootting out of it like crazy. tells me pump working just fine. i would think
tried 2 New caps.
13psi
16psi
no change eather way.
took an extra gasket and put it on the 13psi one to see if maybe the cap still just not sealing.
nope still draining water out of raid. to the overflow
and then out on the ground.
i have no clue where to go from here now.

RE: cooling prob.
 

o yea fan comes onas well just a lil over half on the gauge
so all that is working just fine as well.

RE: cooling prob.
 

son of a bitch, this is a tough one. I misunderstood you, I thought that you were boiling over, but here it seems like your having an issue with over pressure. Hmmm. Does the rad start to overflow right away as soon as you fire up the bike, or does it take a few minutes? Also, you have never dropped or sided this bike correct? And we already sadi that we ran water through the rad and confirmed that there was no obstruction or anything? So basically if this thing is overflowing right away then for sme reason you are overpresuurizing the system, more than it ever should be. If it is happening at normal operating temps then it is also a problem. I think you might have been onto something when you looked at the caps. If that spring loaded part of the cap is not seating well then water will get past it, so is there any chance you have caps for a different model year or something, maybe a radiator off another year? I don't know the history of your bike but if it is all original then we are back to square one. You just gotta keep checking every little thing you can off the list, and your doing a real good job of that so far. Try measuring the height of the spring loaded O ring from the bottom of the cap itself, then check this measurment on the radiator filler spout. THen tell me if you have any scale build up or obstruction that would prevent the spring loaded ring from sealing? Thats all I can think of, confirm all this stuff and get back to me. Also, if you leave the cap off the bike and idle is does the fuild level rise up? I still think you have a bottle neck somewhere and that pump is acting like a pressure impeller. Tough little bastard but stick with it, you will feel great when you lick this thing.