I bought an 08 YZ450F in August. Love the bike. Yesterday I was riding with family and friends when two of the girls stalled their bikes and couldn't get the started again. I left mine idling and helped them with their bikes. When I returned to my bike it was puking water out of the overflow. I immediately shut the bike down and pushed it back to the garage. After it cooled down I removed the radiator cap to inspect the fluid level. Of course it was low because of the puking. The original owner used straight water and water wetter for the cooling system. Not knowing exactly how much water was in the system I dumped half a bottle of Water Wetter in the radiator and filled it up the rest of the way with water, it only took a small amount of water. I then looked up the specs on the cooling system and realized it only holds approx 1 quart of coolant total. I know I should have checked that first! I then started it up and ran it about a half mile up the driveway and back to the garage. I pulled the cap and noticed bubbles at the top of the radiator. With cap on a small amount of water came out of the over flow. Shortened version; 1)riding bike for 20 minutes between 2nd and 3rd gear 2)let bike idle for a couple of minutes 3)bike puking water 4)shutdown bike and let cool off 5)put too much Water Wetter in and some straight water 6)ran bike again and had small bubbles at top of radiator and small amout of water puking 7) put bike away before causing more damage, wanted to consult someone who knows I searched the forum and came up with a couple of good posts but none matched my problem exactly. Just wanted to double check with you guys but so far I think I caused the problem by letting it idle. I didn't know I shouldn't do that. I did put too much Water Wetter in. Is that a problem? Should I drain the whole system now? Is there anything I should check before riding again? What temp should the side of the motor be when hot using a laser temp gauge? I am in Pa and the bike has to be drained in November because the current fluid will freeze. What can I use that will give me good cooling but will not need to be drained for cold weather? I know it's long winded but I don't want to cook my engine. Like the title reads I am probably overreacting but would rather ask some guys who know then cause a bunch of motor damage.