Hondata

You could possibly be flooding it at idle. Try raising the idle waaaay up there and see if it keeps running.

That's not too too hot, is it? Water in a pressurized system will have a higher boiling point, which is why the water's not boiling over right now... if you're belching coolant out of the overflow tank you've got a problem.

First I'd make sure that the temperature is consistent. If so, it's ...