I have an 07 RMZ250 that I just got in the fall. I've only used it a couple times. I haven't fired it up in about 2 months and it's been a cold winter where I live. So i started it the other day (it started right up) and i let it idle for a little bit just to give it a little exercise since it's been dormant all winter. after a few minutes I looked at the bike and there was coolant leaking out of the overflow hose coming out of the radiator? Not sure why it did that? I shut it down for a few. Then re started it and took it for a quick spin and everything seemed fine- the leak seemed to stop. Just wondering why it did that, if i could've damaged something, and how can i prevent.