Radiator Spray

[Rev80210]

So I'm about to take apart my bike and give it a nice custom paint job, but I want to make sure it's running right first. Lately it's been spraying radiator fluid out from the drip can I put on it after riding for about 20 minutes. Is this just because I need to add more fluid, or is it something worse? I just figured it was because there's not enough fluid and it's therefore heating up more than it should and boiling out at me or something.

[gammac]

I'd check the radiator cap pressure. If its an old one it might have lost its zing and be venting too soon.
gammac

[sharka]

it could also be a faulty thermorstat or a problem with the head gasket.

[Sev]

If it's spraying out of the drip can I'd think you've either got too much coolant in there. Or you're pressurizing the system somehow. Likely the above mentioned leaking head gasket or warped cylinder section.

[uncleterry]

Hi all. I just joined this forum. I ride a BMW but my nephew has a '96 ZX9. He doesn't have a computer, so I'm helping him troubleshoot his bike,(from 130 miles away!). He's having the same problem with coolant overflowing when riding, but not overheating.
So here's some questions;
1) If it's a leaking head gasket wouldn't he have coolant in his oil or a loss of power/compression?
2) Should he start over by draining/flushing the system and make sure it takes the specified amount of coolant when he refills it?
3) What's the best way to be sure there's no air trapped in the system?
I appreciate any help.

[185EZ]

I agree with gammac. If the cap isn't holding the correct pressure, it will open to the vent plus it's the cheapest thing to try. A system needs to be pressurized to raise the boiling point of water. I forgot the ratio but for every pound of pressure your cap is rated, it raises the boiling point so many degrees. If you didn't have a cap on, you would overheat quickly. Most shops should have a cap tester.

It shouldn't be the thermostat. If the stat was stuck closed, the engine would overheat and coolant not going to the rad. If the stat was stuck open, the engine would run cold.
uncleterry,
I believe there is a test for the coolant if there is combustion gases present. You may also see bubbles if you can look into the rad opening while it's running. Also pull the plugs, if one of the plugs is bright white, it may be burning coolant from a bad head gasket. There may not be coolant in the oil depending on where the gasket may be leaking. A cylinder base gasket would be more likely to get coolant in oil.
Run the engine to operating temp with the rad cap off. That should bleed off any air pockets in the system.

[uncleterry]

Originally Posted by 185EZ

I agree with gammac. If the cap isn't holding the correct pressure, it will open to the vent plus it's the cheapest thing to try. A system needs to be pressurized to raise the boiling point of water. I forgot the ratio but for every pound of pressure your cap is rated, it raises the boiling point so many degrees. If you didn't have a cap on, you would overheat quickly. Most shops should have a cap tester.

It shouldn't be the thermostat. If the stat was stuck closed, the engine would overheat and coolant not going to the rad. If the stat was stuck open, the engine would run cold.
uncleterry,
I believe there is a test for the coolant if there is combustion gases present. You may also see bubbles if you can look into the rad opening while it's running. Also pull the plugs, if one of the plugs is bright white, it may be burning coolant from a bad head gasket. There may not be coolant in the oil depending on where the gasket may be leaking. A cylinder base gasket would be more likely to get coolant in oil.
Run the engine to operating temp with the rad cap off. That should bleed off any air pockets in the system.

Thanks! I'll pass this on and post what it turns out to be.
P.S. I like your avatar. She has a really nice fish (You Kawi guys have better smileys than we do too!)