1999 Honda CBR600F4.

So I took my bike out for the first time today. When I got into some stop and go traffic, I overheated. I heard the fan turn on several times, but it didn't seem to help.

Tomorrow I hope to change the spark plugs, (obviously unrelated to this problem). So while I am working on it, I will pull the thermostat and boil it with candy thermometer in hand. Approx what temps should it open? 180-195 for a car, but I am unfamilliar with average bike specs.

Thanks in advance, Kevin.

 

Fully open at 194 F for oem stat.

 

Thanks MartiniRossy.

Ok, the thermostat looks brand new. It opened at about 173-175. IDK. I also took the waterpump apart and it looks new.

Throughout the rebuilding of this bike, (Fairings only), I had checked the water a couple times and it always showed full at the radiator cap, but that doesn't mean anything. Is there a air bleeder valve on this bike anywhere?

Any other ideas? BTW, it was about 95 that day and I was in stop and go traffic for about 30 minutes. Might it just be a fluke? I don't want to over worry, but I don't want to lock this engine either.

 

There isn't a bleeder but if you run it for a few minutes with the cap off, that will purge the air out. When it's that hot out, your bike will run warm, but shouldn't overheat. This is what I would do, very easy work. Clean the radiator fins out good, rinse them with water. Flush the cooling system and refill with good coolant. May be an idea to check and make sure the fan is coming on at the right temp also. Should be on between 208-216 F.

 

check fins. and your cap. pressure is key to keeping cool

 

Last week when I went looking at the waterpump and saw that it looked fairly new, I caused an oil leak around the O-ring that goes between the water pump and the engine. I decided to fix it today. While I had the water pump cover off again, I noticed what looks like melted metal. /Shrugs. the fins on the water pump look like they have never scrapped anything, but something caused this damage.

Anyways, I believe I have found what is causing the over heating. At least I hope I have. that little bit of added space would keep the water from flowing as good as it should. It would still flow, but not as good.

Now, where the hell do I find one of these covers? Will it come with a new water pump?

 

So, did you figure out what was the problem with your overheating situation?

 

No. I bought a used waterpump from a bike that was totaled with 5,300 miles. I also got the same thermostat. I have also since put Engine Ice in it.

Last night it was 86. I went for a ride that lasted about 30 mins. I got home and it was about 3/4 on the gauge. I let it sit idle to be curious. After only 2 mins at idle, it was touching the red line.

 

Have you tried bleeding air out of your radiator by having the cap off while the engine is running?
I just changed my coolant with engine ice also and I had the radiator cap of for couple of minutes and rev it up couple time to get the air out. So far my bike is not overheating when I'm riding in 90 degree weather. Try my theory to see if it is that problem

 

any chance the fan is wired wrong & is turning in the wrong direction?
(not blowing, but sucking)