Today i went to the track and warmed up my bike. i have a 03 yz450 I rode a few laps and came back and as i was putting my bike on my stand i noticed a milky substance on my stand. I called my friend over to look at it and he said it wasnt a good sign. i am new to fourstrokes and i wasnt sure what the problem was. He told me it was one a few issues a blown headgasket seal or a cracked head. i checked my fluid in the radiator and it hasnt dropped since the last time i filled it which was about a week ago when we changed the water impeller seal. so my question is, how can i narrow the problem scenarios down. the bike runs strong and doesnt over heat, it doesnt smell like its burning coolant in the oil, its never done this before, and it got below freezing here which it hasnt done in over a year since its warm az. at first i was super bummed and pissed thinking it was somehting serious. i checked my dipstick abd the oil looked fine to me. if the coolant and oil had mixed completely what color with the oil be? im gonna change it first thing in the morning and i wanna know what to look for to determine my problem. im thinking it was condensation from the cold weather and it being run for the first in a week or so. LEt me know what you guys think thanks a lot.